Onboard Video: Pros vs the cons?

[speerchucker]

Yes, I know that in most situations, for most people, using a separate video card is preferable. However, this may not be the case for all users, and hardware is changing.

I'm trying to fully understand a few esoteric issues.

For instance: Many people will simply say "Oh, a video card, ANY video card is SO much better." -but what do they mean? Maybe they are part-time gamers, so they need more performance.

My question is, for a DAW user who does not need much video performance at all, is a separate card still ABSOLUTELY preferable? I use my pc's for live performance, so weight is certainly one issue, one strike AGAINST the card. Also, a card means more heat, which is another problem in a tight rack case.

Here's what I know, or have been told, so far:
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Video cards increase weight & heat. A small but possibly significant factor with a mobile rig.

Video cards, obviously, offer better performance, but only if you re gaming or playing BlueRay for a disk. (given today's better mobos with built-in video)

Video cards require shadow-ram, which can under certain circumstances steal ram from the system. However, with a 256 meg card you should rarely see this.

Onboard video (so I'm told) DOES take directly from the system ram. However, most Realtek drivers pull so little that it's not much of a problem. I AM VERY UNCLEAR ON THIS, AND WOULD LOVE SOME CLARIFICATION.

Onboard video will often increase DPC spikes. However, this is driver & bios dependent. Some mobos running onboard video exhibit extremely low DPClat. Still, this is definitely a concern.

Onboard video uses a bit of cpu power, but not a whole lot.

With some newer mobos, such as the Asus P5Q-EM, adding a video card can actually cause all sorts of problems. That mobo has onboard HDMI, which ou cannot turn off, and it doesn't play nice with third-party drivers.

Mobos with NO onboard video will obviously be simpler to deal with, i.e. less chance of conflicts.
---------------

And that's where I'm at.

I've always used onboard video in the past, but am weighing the pros & cons of adding low-to-med powered cards. One of my mobos has onboard HDMI, but I am even considering replacing the mobo (with a non-audio type) if it makes things more solid.

Any thoughts, or clarification on the above, would be greatly appreciated.

[speerchucker]

Originally Posted by Joe Porto

Why bother with onboard?

I just outlined the reasons, above.

For instance, the performance of the Asus P5Q-EM's onboard video is equal or superior to that $20 card.
The card adds heat & weight.
I have 4 gig of physical ram.

What would be the possible benefits of the card?

[speerchucker]

No, you CAN"T defeat the video on the Asus mobo. You can in most mobos, sure, but not that one.

I don't need dual-display, but the Asus has two DVI outs, in case I did.

If a video card goes bad on a gig, I'm dead no matter what. That's why I carry a spare computer with me. If I were in the studio & the onboard video died, I could STILL add a video card. So, I don't see your point at all.

See, this is the crux of my question. Everyone always says "of course of card is better," but maybe not.

[speerchucker]

Can someone look at the issues I raised in my first post, and comment on them?

[blueguitarbob]

Originally Posted by speerchucker

Yes, I know that in most situations, for most people, using a separate video card is preferable. However, this may not be the case for all users, and hardware is changing.

I'm trying to fully understand a few esoteric issues.

For instance: Many people will simply say "Oh, a video card, ANY video card is SO much better." -but what do they mean? Maybe they are part-time gamers, so they need more performance.

My question is, for a DAW user who does not need much video performance at all, is a separate card still ABSOLUTELY preferable? I use my pc's for live performance, so weight is certainly one issue, one strike AGAINST the card. Also, a card means more heat, which is another problem in a tight rack case.

No, an add-on video card is not absolutely preferable to onboard video. especially with recent advancements in onboard video chipsets. As you mentioned, there are many advantages to using onboard video in system design.

However, I think it is safe to say that even the _best_ onboard video solution can only hope to be equivalent to a low-medium performance video card. The bleeding edge in onboard video is probably comparable to the low range of add-on video from a performance standpoint. That is likely to continue, due to the limitations of using CPU time and system RAM to do video tasks in onboard video.

[speerchucker]

Hey, Bob. Thanks as always for your input.

However, it still sems like you (as everyone) are addressing performance issues.

I'm asking about ram use, cpu overhead, and DPC spikes.

Esoteric stuff, but do you know any specifics?

[tech1]

On-board video on some of my older Asus boards used between 8 to 25 MB RAM. A P4 system with 512 MB physically installed, for example, displayed 504 MB available. A different P4 with 1024 MB RAM displays .99 GB available. I don't have the chipset models on hand right now for comparison, but that's about what I'd expect for any on-board video to use. As far as CPU usage, though, i don't have any data there. Sorry.

[speerchucker]

Thanks, tech1. The big question, though, is what happens if you have 4 gig under XP32.
Does the onboard video really steal from the application memory, as I was told, or from the total memory, like a low-end video card does?

Well, it might be a moot point. I'm considering changing to XP64. - But I'm sure lots of folks might want to know.

[bluehiro]

Originally Posted by speerchucker

Thanks, tech1. The big question, though, is what happens if you have 4 gig under XP32.
Does the onboard video really steal from the application memory, as I was told, or from the total memory, like a low-end video card does?

Well, it might be a moot point. I'm considering changing to XP64. - But I'm sure lots of folks might want to know.

I've worked on many different machines but I've never seen a computer with 4gigs of ram, XP32, and integrated graphics. Hopefully someone else can answer your question.

Personally I have used integrated graphics for many of my computers, especially servers and basic use machines. Personally I really like the new "high-end" onboard video cards such as the latest from AMD and Intel. Built-in HDMI, built-in dualhead, built-in h.264 decoding; really if you're not gaming there is no reason to go with a dedicated card anymore. From an upgrading standpoint I would still prefer a dedicated card, but most people don't rebuild their computers as often as I do.

Go with integrated and don't worry about it pulling from your system memory, if you have 2gigs+ it really won't matter. When all it's doing is rendering you 2D desktop view it's only going to take 12-32mb of ram, which is practically nothing.

[blueguitarbob]

Originally Posted by speerchucker

Hey, Bob. Thanks as always for your input.

However, it still sems like you (as everyone) are addressing performance issues.

I'm asking about ram use, cpu overhead, and DPC spikes.

Esoteric stuff, but do you know any specifics?

Okay, I'll try to concentrate on those three points. I was tired yesterday from work, when I wrote the previous post.


Onboard video uses the CPU as a software-emulated GPU. It will use processor time, definitely. How much? It depends on the driver and the CPU. With the fast processor chip you are talking about using and the relatively fast memory bus on that Asus mobo, it probably won't be much, but it will be more than zero. An add-on video card will use (almost) zero CPU time. I don't know if the difference will be significant in your application, but there will be a difference.


As for DPC queue problems... I don't really know, because I don't think it's possible to make a general prediction. Delayed procedure calls shouldn't build up in any system. If you are experiencing large queues of DPCs that are eating up significant CPU time, that is an off-nominal condition. It indicates that the CPU is not able to manage the demands of the hardware fast enough, and needs to delay some of the lower-priority calls until "later." It's a virtual trainwreck and probably indicates a bug in a driver somewhere. No software engineer would cause a buildup of DPCs on purpose.

I would think that you would decrease the chance of that happening by having a very fast CPU and a very fast memory bus. I _suppose_ that onboard video could make the problem worse, because it is demanding processor time via procedure calls... but I don't think this is a major decision point in choosing between onboard vs add-on video. It's more of an overall system stability issue, so you have to consider the system as a whole.

Theoretically... using a mobo with all necessary hardware integrated onboard would (hopefully) indicate that the hardware drivers have all been tested and verified as a system. It _should_ result in a more stable system, and lessen the chance of off-nominal conditions, such as DPC queue buildup. When you build a system by integrating parts from different manufacturers that communicate at a low level, you increase complexity and therefore increase the chance of issues like DPC queue spikes.

In reality... consumer computer products are not engineered or tested like industrial systems are, and that theory doesn't apply. Integrated mobos sometimes take several BIOS and hardware driver revisions to sort out conflicts. Some established add-on cards are extremely stable additions to any system. Major OS changes (I'm looking at you, Vista) can throw hardware stability out the window. It's a lot easier to build a high-reliability system from comsumer parts than it was in the 90's... but I still wouldn't use one to fly a plane.


As far as the impact on system RAM, I outlined a scenario where onboard video would reduce system RAM at the end of this post:

http://www.gearslutz.com/board/3793559-post31.html


However, onboard video does not _automatically_ decrease the size of your available system RAM. It depends on the specifics of your system, and you can choose components and settings to make it less likely.

With onboard video, you can (usually) select the size of the video buffer. If you are only doing 2D display, you just need enough to support the resolution and bit depth of your displays. That's probably small... maybe 128-256 MB, if that. With a small video buffer, and 4GB of memory installed on the mobo, I doubt you will see a system RAM difference between onboard and add-on video.


Does that help at all?

[speerchucker]

Bob,

As a test, I just installed a 256 meg video card in my new Asus P5Q-EM. Compared to when I was using the built-in video, set to its lowest power in the bios, with the third-party card I actually GAINED 250 meg of system ram! (as shown in the task manager.)

With this mobo, I didn't see a change in DPC spikes, but still that a pretty significant gain. Interesting.

[jcschild]

HI,

onboard video is fine with the right mobo.
(assuming you dont have waves as it requires open GL)

it should not give DPC issues at all.
does not use enough CPU power to be a concern and in 2d should never touch your ram.

we do a good amount of 2U samples boxes they always have onboard video.
never been a problem.

Scott
ADK

[speerchucker]

Well, my personal results are the opposite, what can I tell you?

Each system will obviously be different.

[dstroyallmnstrs]

Scott is right. First of all *intel* onboard graphics are crap. Both Nvidia and AMD are putting out creditable onboard graphics integrated into their chipsets.

Most of your other questions can only be answered with specific chipsets and specific motherboards. There is no all in one answer for this.

If you're going to go only with intel boards the only decent onboard graphics will be from Nvidia as AMD/ATI no longer make chipsets for intel. Research if there's specific memory allotted only to the graphics (there is on the amd/ati side).

[jcschild]

i would add to this that the boards i use for the 2 U are nVidia chipset!

Scott