Thonex SX test on a QuadCore with weird results...

[UnDeFiNeD]

Hiya computerslutz!

I used to be a systembuilder, but am now practicing mixing engineering full time.

To do all this in speed and style, I made myself a nice PC, with a Core2 Quad Q6600, 2048mb DDR2-800, asus p5w DH deluxe (975x chip) and a EMU 0404 as audio interface.
Now, because I run Cubase SX3.1, I wanted to do some benches like Fivetowers and Thonex, but the latter gave me something weird to think about.

When do you normally start to hear cracks in your audio? when u are overloading the cpu, right? Now with the thonex test I wanted to see how well it responded on 2ms ASIO latency, so I put it on 2ms, and pushed play...
CRACKLE...kkkrt...crack...crrrnnnchch.....etc..

Now while this isn't THAT abnormal, when I looked at my cpu meter, it was only at 40% bouncing agressily to about 50%, no cpu overload it seems
I opened my windows cpu meter and saw four cpu's barely touching 30%


Now my question to you is, what is then the cause of these cracks and dropouts? I was allways convinced this was cpu headroom, but I clearly still have enough of that, also the ram was at about 500mb (of the 2gb) so that wasn't it either.

screeny of the test:


Thnx!

[manning1]

un....
i dont know if this is true in your case...
but ive typically found that "audio hiccups" can sometimes be caused by another device takeing over the bus from the sound device/sound card.
ie..."locking it out".
assuming the 0404 is a pci card ??
the only reason i can think is another pci device impacting on the pci bus. what do u have in your pci slots other than the 0404 ??

OR another windows task takeing over. assuming the 0404 drivers are copacetic/
working properly.
by the way no mention of your hard drives.
i prefer 16mb cache hard drives.
all the best.

[UnDeFiNeD]

only thing on the pci bus other than my 0404, is my UAD-1 card
I didn't mention my harddrives because normally they shouldn't have any effect since all data is loaded into ram memory.

[True North]

Have you been on the Nuendo forum yet ?

Some of your problems are unique but it appears as if Steiny has some issues with properly managing multi-core. It is most noticeable on Dual - Quads. Performance scaling goes out of whack when using latencies of 64 samples or less. Differences between the Task Manager and the Steiny SPU Meter and other multi core issues have been noted in the thread below

http://www.nuendo.com/phpbb2/viewtopic.php?t=13317

there is some good info on the above thread - a lot of bickering BS as well but it is worth the read. The long and short of it is that Steiny admits that there is a problem with their programming and how it manages multiple cores. They are forecasting a fix in about 6 months.!!!!

You should probably try posting at the Nuendo forum as well, good luck

[manning1]

un....
just a couple of comments.
in addition to TN's valuable comment.
well actually day in/out hard drive performance is rather important.
particularly ive found the larger the cache in drives the more that daw applications seem to like this fact. which is why i normally recommend drives with 16 mb cache for heavy audio work. remember...drive cache is a temporary holding area in the read/write process.

secondly the fact that you have another pci device ....not saying it is...
but it might impact the 0404 depending how much pci bandwidth is being used by the other pci device.
the pci bus is no different than a highway carrying cars in simplistic terms.
and like a highway , when traffic is low, and maneageable all is copacetic.
but as traffic increases...well...u get the idea. traffic jams can occur.
whether this is occurring in your case ...i dont know.
but at the least i would try running the 0404 by itself and see if things clear up.

me personally if i'm useing a pci sound device i dont put any other device in a pci slot to ensure the sound card has full rein over the pci bus bandwidth.


however as TN says.....mebe this is a known issue. but if were me...
out of interest i would run the 0404 by itself n see what happens.

[clonewar]

I agree with manning1, the first thing I would do is pull out the UAD card and try the test again. Were you running any UAD plugins in the test?

Also, don't rule out problems with the soundcard drivers. If you have another one (or a friend that can lend you one) it would be worth trying it out.

Lastly, read the thread the True North suggested. It is true that Cubendo has an issue with multi cores, but from what I've gathered on the forums it really effects dual quads. I know there are people on the Cubase forum running the Core 2 Quad with success.

[Animus]

I was getting the same symptoms at lower latencies with the same motherboard. THere was a setting in the Bios I "thought" would make things better, where you can switch the buss priority to PCI --> PCIExpress and vice versa. I switched it to PCI as I run UADs and Powercore in a Magma and a Multiface. Later when going to lower latencies I got these crackles I had never gotten before and it took a little troubleshooting until I remembered I had made that change in the Bios. I set it back to the default of Pci Express priority and all was fine again. Weird.

[UnDeFiNeD]

Were you running any UAD plugins in the test?

Nope, it's a standardized Cubendo benchmark I got from ADK proaudio, called "thonex test"
It only uses default, native plugins so I would be amased if my UAD has anything to do with it.

Also, don't rule out problems with the soundcard drivers. If you have another one (or a friend that can lend you one) it would be worth trying it out.

I also have an digi mbox2 hanging on USB (as a PT dongle ), I'll see what she does, but the main reason I bought the 0404 was because it's PCI and therefore has a lot less latency than a USB/FW interface like the Mbox.

It's worth nothing that when I tried the test at the 3ms setting, everything was running just fine, so it's not that I'm desperate for 1ms less, I just want to find out why he suddenly craps out like that at 2ms while the cpu's are barely working.