Disk Too Slow Messages In Mac Quad with RAID setup

[NoizyNinja]

So I upgraded to the G5 Quad (not ready to do the Intel thing yet) and I installed a 4 disk RAID 0 (from MaxUpgrades.com) and started working in Logic at 96k. It kept on choking with less than 20 tracks. When I was recording I could barely get it to record 10 tracks without it stopping with 'disk too slow' messages.

Set it on the 'larger disk buffer' option and the same result. The system performance meter (in Logic) on the disk i/o was peaking. My Xbench readings show 250MB/sec sequential write. That spec sounds right for a SATA RAID 0 of 4 disks.

Anybody out there recording in 96k with a Quad & Logic getting lots of track counts? I love to hear how you do it. How does Pro Tools get it happening. The track counts should be a function of disk speed, not from PCI cards. I could be wrong though. Any clarification would be appreciated fellow GearSlutzs. I'm going back to 48k for now. 96k sounded sweet. I'll miss it.

[manning1]

you didnt mention what model drives your useing.
model numbers would be helpfull.

[NoizyNinja]

4 Maxtor SATA 500GB drives (3H500F0). Here;'s the link:

http://www.maxtor.com/portal/site/Ma...uickView%20500

[manning1]

well theres not exactly a ton of info given on that drive.

i googled elsewhere looks like it has a fat cache. good.
if youve already run a seperate disk benchmark utility to confirm the drive is operating up to spec then i would talk to maxtor tech support.
or maybe try a faster rpm drive. and see if that solves the problem.
i'm no mac expert on mac internals...but if you have low memory in the g5 then
this might make an impact maybe.
how much real memory you got ??
somethings certainly fishy somewhere.
given the drive stated performance specs .

i checked that maxupgrades site.

so i understand the drives are linked to the g5 through something like a interface card. correct ??
i see model p/n's like this....>>>SZ-MCCBA46L250
please confirm your use of this card plus model number.
which one are you useing...??

also a point to NOTE....not sure tho'.....
i notice the interface cards on maxupgrades refer to specific hitachi and maxtor models. different it seems from the maxtor drive your useing. i'm left wondering if this might be a point or not.
you might want to DEFINITELY make sure the paricular interface card your useing supports the specific maxtor drive your useing.

[NoizyNinja]

Thanks manning1. Something is fishy. There's 4 GB of ram. Should be more than enough. The math should be there in terms of x number of audio tracks at 24bit/96k. How many MB/s would that be for 40-50 tracks approximately. That should be less than the 250MB/s the RAID is doing. Or maybe not...

[manning1]

dont quote me..cos computers are funny....lol...
but with that level of memory i would expect you would get what you want.
get back to me on the model of interface card your useing from upgrades.
just for my further looking at its specs plz.
ps...gonna go n;' do some maths...be back shortly cos i dont record at 96k. did you try 88.2 ??

[manning1]

ok...some maths.....allowing some safety margin i get roughly
(i rounded up 96k to 100k samples per sec.....and assumed the sample values were stored in the host software in 4 bytes. lets say. .....the prob is i dont know how your host ...logic ?? stores on disc....but lets say 4 bytes....therefore 400k per sec of 96k audio for one track roughly.)
thus 1.2 meg per sec is 3 tracks .
12 megs per sec disc 30 tracks.
unless my maths out somewhere it looks like your system should handle the load.
ah....but wait.....lets look at memory.
30 tracks of one second stored in memory seems to be a problem but as most host software is prolly only storing in memory at any one time only a few millisecs worth of each of the 30 tracks.....
see howthe maths gets interesting ??
so lets say 10 milli secs of each 30 tracks is stored in memory.
AT ANY POINT IN TIME.
that would seem to indicate your memory should handle it DEPENDING HOW THE INTERNALS OF YOUR HOST SOFTWARE WORKS.
IF YOUR HOST SOFTWARE IS STORING one sec of each of the 30 tracks in memory however at any point in time....maybe memory is an issue. i didnt program the internals of your software...thus i dont know what it needs in terms of memory at 96k.

hmmm had a thought.....do you have a utility that monitors memory useage ?? while applications are running ??
i'm sure they are available for mac.
maybe you want to run the utility at the same time your multitrack software is playing back tracks.....and get a true read out of physical memory useage by logic. this way youll get closer to the TRUTH of whats really happening. this is what i would do.
you see it might be that logic is reporting discs too slow whereas in fact the prob is not enough real memory is available.

[NoizyNinja]

Very interesting manning1. You're not just a dumb computer eng : ) I had a feeling it might be Logic. The reason I put 4GB of RAM in there is because Logic only addresses 3.5 GB from what I heard. In the Activity Monitor it shows Logic is using 415.41MB of real memory. That's low huh? You're a real help! Thanks!!!

[manning1]

ninja....
it might not be a logic issue tho'.
dont be quick to blame logic. i wouldnt assume that.
maybe logic...TO BE FAIR....is getting its performance stats from the operating system. if the OS is misreporting....this might be another area to look at.
please confirm how many tracks at that memory level.

if in fact that low real memory level is correct then this would suggest that logic is very efficient in memory useage....and is being very clever by not dragging one second of 30 tracks into memory at one time......but milliseconds instead in little what are called memory array buffers. thus kudos for logics efficiency to be fair.
in memory useage.

by the way we havent talked about your sound device.
what are you useing as your sound device ??
do you have a feel also for your buffer allocations in logic ??
(if it lets you do that which i'm sure it does.)

anyways...off to the land of nod .....need my ugly sleep....lol
perhaps we can continue tomorrow...cos i would like to help you nail this down....all the best.

[NoizyNinja]

Yes that's right. Here's the screen pic. 18 tracks are going. It helped to rnder them so now it's reading each as a single file. No edits.

[NoizyNinja]

Good night manning1. Thanks for your help!

[manning1]

ok......NOW I SEE WHY LOGIC IS REPORTING THE DISC SLOW....
NOT LOGICS FAULT.....
LOOK AT YOUR VIRTUAL MEMORY IN LOGIC PRO......
ITS USEING LOTS OF DISC AS MEMORY.
a slower method than useing real memory.
i'm real glad you showed me that activity monitor.
THAT EXPLAINS A LOT.

[NoizyNinja]

I can't seem to lower it. Would it be using the RAID disk as memory or the boot up disk? I don't know if it's something I can mess with though...

[borjam]

Have I seen something called "Intego"? Are you using antivirus software?

Delete it. Period. It's a waste of resources, and it kills performance.

And always helpful to limit what you are running. Even though you have a very powerful machine, it's good to stop anything you don't need.

But if you are using an antivirus, I'm pretty sure that's a problem.

[manning1]

ninja....
ok....i got sleep. refreshed. twas zonked last night.
as i said ive never worked for apple so i dont know the deep internals going on/interraction tween the OS and logic.
but i have worked on OS's in the past.
(also check out borjam's good point. cos anti viriii/security running can impact pc's performance.)
anyway..heres what i SUSPECT might be going on in your mac.

somewhere is a setting thats keeping maybe useage of real memory down (under
half a gig from that monitor report).
THUS this is bumping up the virtual memory useage.
now...if your not aware...let me explain the concept of virtual memory.
(win xp does the same thing. )
in many respects virtual memory in laymans terms is a "fallback" .
it was designed so that on low memory systems hard disc was used
as "fallback memory". HOWEVER THERE IS A DOWNSIDE.
follow me here.....in something like a text editing app or simple office apps....
as they are not as intensive as audio the use of disc for virtual memory is often ok. BUT FOR AUDIO....the downside is what is called "PAGEING".
ie.....the OS (in this case the apple OS) has to keep on pageing to and from disc.
THUS A PERFORMANCE HIT IN MANY RESPECTS....cos pageing is slower than access to real memory.
think of it ninja CRUDELY like this.
in laymans terms......i want a cigarette...so i reach for my pack of cigarettes next to me (REAL MEMORY).....versus going to the store everytime i need a cigarette , and jumping in the car etc. (VIRTUAL MEMORY.).......ie....the latter is much more inefficient.

bottom line you prolly are getting the message from logic about disc too slow cos
a lot of disc activity is takeing place re pageing.
therefore you should prolly look for a setting that lets you up the real memory useage by logic and limit the virtual memory useage.
i dont want to mislead you....so i would talk to an apple tech on how to accomplish this. Its prolly a setting set by user in the apple OS.
in summary....audio apps can be really impacted by heavy use of disc for virtual m,emory and performance impacted. this i think is the root of your problem.

i have a suspicion.....could you do something please ??
very simple.....just record and playback one track......and post back a picture of your activity monitor in each case please.
hope this helps.

[manning1]

more.....
ninja....look at the very bottom of that activity monitor.
SEE ALL THAT LOVELY REAL MEMORY FREE ??
BEING UN USED ?? now look at the pageing.
definitely fishy......
COS THE MAJOR QUESTION IN MY MIND IS WHY WITH ALL THAT FREE UNUSED REAL MEMORY IS SO MUCH VIRTUAL MEMORY BEING USED.
see what i mean ??
this suggests a setting somewhere.
ps....i see no anti virus process running.
according to the monitor.

[manning1]

much more....
ok...been doing some digging.
but need some questions answered/confirmations.
cos i find this interesting/so i can help further.
1. your running OSX right with logic version ??
THIS IS YOUR SYSTEM...right ??
http://store.apple.com/1-800-MY-APPL...amily=PowerMac
and this link showing the internal architecture....
http://developer.apple.com/documenta...510_archi.html
correct ??
2. these tracks your running....are any loading big samples ??
(where virtual memory might be allocatted...)
or just vanilla recording/playback at 96k. ??
3. your running this drive array raid thru a controller card in a pci slot in the mac.
seperately i assume you have a system disc ?? on which the OS resides ?? ie....not on the recording raid array ??
is THAT the set up ?? plus 4 gigs ram.
it would be helpfull to know the controller card model number so i can look up its specs
on the manufacturers site. a possibility is even though one might use hi thruput drives maybe the controller card
cant handle all the activity. but i wont know less i look up the specs from the manufacturer.
4. lets talk about your virtual memory cos i think this might be the heart of the problem.
very important. WHERE IS THE VIRTUAL MEMORY RESIDING ??
as i stated it will be residing on a drive of course.
now....heres my concern....IF the virtual memory is being swapped in/out to/from
THE SAME DRIVE as recording is occurring...this might impact performance.
OR....is it set up on the system drive instead of one of the raid drives ??
let me explain.....in an ideal daw IF recording is being done to the same drive as the OS/virtual memory resides on ....then this can impact
audio recording cos the OS needs that drive. and controllers have a finite thruput.
5. in logic preferences ....do you see any settings regarding real memory useage versus
virtual memory useage ?? it might be under a performance tab for example or project settings whatever.
been awhile since i used logic. ie...do you see any optimisation
settings in logic ?? AND are you sure the project recording path
is set correctly ??
get back to me. peace...will continue digging.

ps.....for your own education/understanding in the second link showing the architecture
of your mac notice very carefully....some important aspects of this computer architecture....
and its an interesting point. your raid array is linked to a card sitting in a pci slot it seems to me
that communicates with the MID BRIDGE...notice also then everything flows thru the NORTH BRIDGE..
via hypertransport. now NOTICE a very interesting aspect of the hypertransport....viz......two way at
1600 mbps. YOU SHOULD BE AWARE OF THIS. in laymans terms this means an UPPER LIMIT AS TO HOW MUCH CAN BE PUMMELLED THRU THE HYPERTRANSPORT....NOW...what does this mean to you in real every day terms......the answer is simple......although on the surface it would seem (eg new hard drive technology...) that you could put better and better drives over the years in.....in reality your limited by the upper limit performance spec of the link tween north bridge and mid bridge.
its very important you understand this aspect. in summary.....dont assume that higher performance hard drives will overcome this aspect. ALSO NOTICE that everything passes thru NORTH BRIDGE on the way to the PROCESSOR MODULES.....very interesting this is.
in laymans terms therefore when logic is say doing some dsp on a track ...eg....lets say putting reverb on
a vocal track....real memory will be used. NOTICE the location of the memory bus off of northbridge as well as the processor module communication...thus it all is commanded thru northbridge.
i just wanted to alert you to these aspects so you realise there are upper performance limits.
of the different modules within the architecture irrespective of other aspects like memory and disc drives.

now lets look at south bridge. if you notice ....two internal hard drive connectors. i suspect this is where your MAC OS system disc is residing.....please confirm.
in summary the raid array is communicating with the MID BRIDGE and the system/OS with the south bridge.
now if you notice in addition there is room for another hard drive off the south bridge.
this might be usefull to you in the future. its very important ninja you understand this
architectural diagram of your mac to allow you to set it up in an optimum fashion.
ie...really try and understand the architecture.

ONE FINAL ASPECT to be aware of......if say your useing firewire sound devices for example. notice carefully they are linked to the SOUTH BRIDGE.
this link will have an upper limit of transmission also.
for example theres good old south bridge working away nicely with the system drive but it also must deal with the firewire sound devices demands.
NOW on the other hand be aware if you put a pci based sound device into your mac this will be serviced by MID BRIDGE.....oh dear but mid bridge is already also serviceing the raid drive array. thus ask yourself what added impacts might be realised by a pci based sound device and the added impact on mid bridge. ??
interesting stuff huh ??
really in laymans terms its no different than waiters in a restaurant put simply.
the different componts are just like waiters servicing the different modules (clients.).....but problems can occur if the waiters are driving themselves bonkers....lol...cos there are too many patrons to service.
hope i explained this ok.

[NoizyNinja]

Good morning manning1. Thanks for checking this out. Lots of good interesting theories.

1. Yes

2. The tracks I am running are 24b/96k audio tracks. 18 of them.

3. Yes. The OS is on the boot up disk and then there are 4 other disks which are in a RAID 0 array on a Highpoint Rocketraid 2310 PCIe card which states it's compatible in all the slots (x4, x8 and x16). I put it in the x8 slot. I have 2 UAD cards (which say they are compatible in all slots too) in the x4 slots. The graphic card is in the remaining slot. I might mess with rearranging this to optimize.

4. I though of this too. The virtual memory being o the RAID disk. There is 1.7TB on there available though. No way for me to tell.

5. There's not much to play with in Logic in terms of optimization. The record/song path is set correctly.


There is no Virus software. I think that's my backup software. When I'm doing critical mixing I streamline the apps. The free memory vrs VM thing is weird. Why create VM when you have so much free? I might try to get a tech but I don't know if I have a day to stay on the phone with them. It's also iffy who you get to talk too . This seems to be some advanced stuff here. There aren't many user tweakable settings for this. It's Mac's world. I will take all this into consideration. DO YOU THINK THE SLOT THE CONTROLLER CARD IS IN MAKES A DIFFERENCE? I might disengage the UAD cards and see if there is a difference. The RAM stuff is weird though. Thanks again manning1 for your expertise!

[manning1]

ninja....stay on line....
ok now you tell me lol !!
you ALSO have other cards in the pci slots right ??
well hell man...the uad cards plus all the other stuff like the raid might be overloading the pci bus.
please confirm uad cards in pci slot.s.....

[manning1]

in addition i noticed a note i dug up on your machine.
please confirm this.
apparently the system disc that shipped with it.....i believe is a 8 mb cache hard drive. in this note it suggested one could upgrade the system disc for better performance. you might want to check this out.
see this link....
http://www.amug.org/amug-web/html/am...articles/quad/
on system drive upgrade.
cos it would mean prolly your OS would perform better.

please also confirm where your virtual disc is set up...in the raid array ??
not sure i like that idea cos it means more work for the raid controller.
if were me i would try and set it up off south bridge thus relieving the load...but i would discuss this with a apple tech.

fascinating stuff...lots fun.
i suspect youll see some difference if you disengage the uad cards.....
but run a test to confirm please.

[manning1]

please confirm....
is THIS your highpoint card......??
http://www.highpoint-tech.com/USA/rr2310mac.htm

ok it looks like its hi performance....BUT BUT BUT....
notice the mid bridge. and north bridge.
in one of these bridges might be .....not saying it is...just might be where a bottlekneck might develop.

one other thing. you might look out for.
IF WERE ME> i would be looking for a utility that can monitor
in real time the total activity of the pci slots.
this might be usefull in determining any bottleknecks.

for example on pc's i normaslly advocate folks to be carefull loading up pci slots cos there is an upper limit to pci bus thruput.
and the same situation can arise on a mac. youll have an upper limit on pci bus thruput no matter how well performed the devoces in
the pci slots are. that mid bridge is in ESSENCE ......GOD !!.....lol.
do you have anything that lets you monitor in osx the total load on the pci bus just like you can monitor the cpu load ??

like you i find it weird why more real memory is not being used versus virtual memory. its as if virtual memory is automatically being allocated irrespective of real memory level.
if this is the case ......and it cant be reset somehow...its crucial that
.....i would think anyway....not to put virtual memory on any of the raid drives to leave them free for recording....and lessen total load on the pci bus/mid bridge.

you see my main concern is that logic is reporting disc too slow....
BUT IN REALITY cos of your raid set up the OS might be reporting to logic (treating the raid as one hunking big storage array...)
whereas its the pci bus reaching its limits in reality.
not the disc drives per se....see where i'm coming from ??
so i suggest this aspect be checked out.

ok...did some more checking....not sure of this....but one note suggested you can check disc drive (an other activities....uad maybe ??)... useing the mac activity monitor. could you see if you could do this please ??
this might give us added clues for bottleknecks.

in addition ...one final point.....your not perchance hooked up to the net hi speed
are you while recording at the same time...cos this might impact performance !!
according to one note ive seen. and this can be true on pc's also.
i know this from experience.

also ive come across mac osx tuning sites like this one for example....
http://www.thexlab.com/faqs/performance.html
be carefull !!! dont do tweaks that might compromise you.

please tell me if you nail down EXACTLY where your virtual memory is located....
this is very important.
OK I FOUND IT.....you can monitor disk activity from THE DOCK.
look for.......SHOW DISK ACTIVITY. read this link....
http://www.diveintoosx.org/panther/p...anagement.html

phew......lol.
going for a cuppa tea.....will check back in an hour.lol.

[NoizyNinja]

Hey there. Stepped out for a sec. Lots of stuff. Yes that is my raid controller card and yes there are other cards there and I suspect that is the culprit. Those cards are the main reason I'm not on the intels now. Nope I'm not online during critical mix, rec. My laptop's for that. Here are some photos of the disk activity. Notice the drop in pic 1. That's where it quits. Logic has a disk i/o meter that shows nothing for some strange reason. I will explore further.

[manning1]

ninja...
those dont seem high transfer speeds,....

we really need to find where your swap file is located that holds virtual memory....
from my digging its hidden.
look for private/var/vm
if you can search for this directory it will tell us where the swap file virtual memory is located. on which disc drive.
by the way i came across a utility called swap cop ...are you aware of this ??
but i wouldnt muck around with it just yet. just be aware of it.

until i know what version of mac osx your running.
please be exact.)
could you please tell me so i can do some more digging plz.

in addition you havent told me about your sound card or sound device.
i would like to know that plz. WHAT IS IT ??
firewire ?? off of southbridge or ??? what ???

also heres another thing you might try as an experiment.
southbridge shows support for two drives....one additional to the sustem/OS drive. have youever put a second drive off southbridge and tried recording to it and seen what performance you get ??

the other test i would do is run minus the uad cards and then lets look at the activity monitor...and look at the differences in performance. for example do you get ...AND I WOULD REALLY LIKE TO KNOW THIS...logic telling you disc too slow once uad is taken out of the equation......and heres the telling point...IF LOGIC DOESNT REPORT DISC TOO SLOW WITH UAD DISENGAGED....then there might be an issue running the uad's at the same time as the raid drives off the pci.........ie....maybe the pci was overloading perhaps/bogging down. are you running some intensive plug ins on the 18 tracks ??

[manning1]

ninja.....
also now lets talk about those uad cards for a bit.
if these are older cards.....do you know for sure they will work in your g5 ??
are they old cards ?? from another system ??
and are they compatible ?? this could be another aspect/situation.
if so....i would check with uad on two points.....
1. that they are compatible with your g5.
2. that there are no issues runnig at the same time with a raid set up like you have.

on the other hand if the particular models of uad you have are known to be compatible with your g5 and its osx version as well as logic as well as running a raid confign at the same time... then this shouldnt be an issue.

[NoizyNinja]

I've been working with the computer and I think the big problem is working in 96k. 96k does sound really good (more information) but I have to dither it down anyways to CD or mp3. I think working in 96k is 'clogging' the pci bus and that's what's triggering the messages. I now have been working in 48k and it's much better. I don't think there is a substantial difference between working in 96k and dithering down to 44k vrs. 48k down to 44k (that's for another thread). The load on the machine probably more than doubles and the pci bus gets jammed with lots of audio in & out of the Highpoint and UAD's. So it was fun to see where the limit was but now I'm back to 48k and there seems to be a nice ceiling to work with. Now there's a whole issue I've noticed on the Logic threads on Apple's site that deal with Logic's inability to fully use all four processors. It really only addresses two. It seems to be a software issue that was fixed in the last revision for the new Intel quad's. I feel like a stepchild. Many are speculating that Apple won't fix it. I think it's a fast computer anyways. Thanks very much for the lesson and help. I'll let you know if 48k causes any issues.

[manning1]

ninja...
my understanding was logic only uses 2 .......performer...all ??
anyway in closing if i had your machine i would prolly test out putting another drive off southbridge ....and putting the virtual memory ON THAT DRIVE.
on its lonesome.
(but i would check with apple support first.)
my theory is that in engineering terms by putting swap on its own drive it neither interferes with the OS drive calls or the recording drive calls performed by logic.
frankly i think there are some issues in your system.
and with that power you have i really feel 96k should be achievable.
but its difficult to test stuff out when i'm not there.
all the best.

[dkatz42]

Originally Posted by manning1

ok......NOW I SEE WHY LOGIC IS REPORTING THE DISC SLOW....
NOT LOGICS FAULT.....
LOOK AT YOUR VIRTUAL MEMORY IN LOGIC PRO......
ITS USEING LOTS OF DISC AS MEMORY.
a slower method than useing real memory.
i'm real glad you showed me that activity monitor.
THAT EXPLAINS A LOT.

Sorry, but no.

Look at the "page out" count. It's zero, as it should be, which means that nothing has been *written* to disk, which is as it should be given the huge amount of free RAM.

The VM size reported that is not in real memory is any application code that has not been executed (and thus not loaded into RAM.) Unlike the bad old days, applications aren't loaded into RAM and then run; rather, the disk image is mapped into VM, and then any code that needs to execute triggers a page fault and the page is loaded into RAM. This is a huge win, as it doesn't clutter RAM with a whole bunch of code you will never execute, but it does mean that any code in an unloaded page will come in from disk when first executed (not a big deal.)

Please do not spread misinformation.

[dkatz42]

Originally Posted by manning1

more.....
ninja....look at the very bottom of that activity monitor.
SEE ALL THAT LOVELY REAL MEMORY FREE ??
BEING UN USED ?? now look at the pageing.
definitely fishy......
COS THE MAJOR QUESTION IN MY MIND IS WHY WITH ALL THAT FREE UNUSED REAL MEMORY IS SO MUCH VIRTUAL MEMORY BEING USED.
see what i mean ??
this suggests a setting somewhere.
ps....i see no anti virus process running.
according to the monitor.

See my earlier response. You're barking up the wrong tree.

All that unused RAM is unused because it's never been needed. (Rant about people saying "more RAM is always better" deleted.)

[NoizyNinja]

Hey dkatz. So what do you think the issue is? PCI being too slow to handle all that info going i/o the RAID controller card and the 2 UAD cards?

[manning1]

katz....
then heck....where do you see his problem ??
if you have intimate knowledge of this at the engineering level feel free. go to it.
cos i was zonked last night.
so are you saying the vm is just reserved but not actiually used ??
i'm well aware that in todays architectures the whole thing isnt loaded into ram. actually its not really a new technique.