GPU/buying a new card vs faster CPU

[Jeff Harper]

GPU acceleration feature is nice to have. Let's get that out of the way. It's not working for me, but for some editiors it's giving outstanding results, and for those of you for which it works, great.

On the other hand, I'd like to encourage folks to take advantage of the untapped potential of their CPUs. Or if you're considering a new video card, look at your current CPU first. If you could do better, I suggest forgetting spending $$$ on a fancy video card until you've replaced your processor first, as that is where the real potential rests in squeezing performance out of Vegas.

Here's why I say all of this. This morning, after a couple of months with my new processor, I finally stumbled upon the correct OC settings, and the difference is quite something.

Disclaimer: Overclocking is not for everyone, but can be learned with a bit of research.

I'm finally running at 4ghz stable for the first time, and the speed in rendering is much faster, playback of 60p files is perfect in best mode with four cameras. Programs open nearly the instant I click on the icon, the system is much more responsive. I have been overclocking for a few years, using setting I picked up on the web, and have always wanted to hit 4.0, and it finally happened, and man is it worth it.

If you have a board that will OC, I'm simply saying don't waste it, use it for all you can get out of it. It costs you nothing and will give MUCH better results then GPU acceleration. If you can add GPU acceleration into the mix, so much the better, of course.

A work to the wise: CPU speed is not the only thing you need for good Vegas performance. You need adequate hard drives to get full performance from Vegas also. Slow drives will slow everything down, including playback. But as long as your drives are adequate, and you have a sufficient power supply, I say go for it.

[Mark Davidson]

That's some useful info, thanks for sharing.

I've got a MSI motherboard with switches that allow overclocking at 10, 15, and 20%. I've been researching better video cards and more memory, but will test this first.

[Jeff Harper]

Good luck Mark. I know on my board the presets for overclocking don't work too great, you kind of have to get in and do manual settings, but maybe you'll have better luck

If you haven't overclocked, you will want to find the forum for your board to get the settings for you processor, which for my processor I still haven't found. I'm tweaking settings from another similar processor. So far I'm running my 3.33 chip at 4.2 on the stock cooler, which is pretty good, considering that my temps don't go above low 70s during a Bluray render.

Download Core Temp to monitor your temps while you're playing to ensure your in the safe zone for your chip.

[Randall Leong]

Jeff,

That's a good word of advice for anyone who is using or buying Vegas Pro 10 or 11, and has an already underpowered system in both CPU and GPU. However, there are limits to this: It happens every so often that the motherboard someone is using cannot support any faster CPUs (meaning that his system's currently installed CPU is the fastest it will accept) and that his CPU has already been overclocked to its maximum stable speed - and yet his system still underperforms with his currently installed GPU. In that case, an entire new system may be in order for that user.

By the way, unlike the GPU acceleration mode in Adobe Premiere Pro CS5.x, the GPU acceleration mode in Vegas Pro 10 or higher doesn't improve the image quality one bit (that improvement is done entirely in software using the CPU). If one is using Adobe, on the other hand, a simple switch to an Nvidia GPU (that Nvidia GPU does not have to cost $300; even a $125 model would perform quite nicely) would have improved matters significantly since the GPU mode in Adobe offers significantly higher image quality than the software-only mode at default settings (and that the GPU mode currently supports only Nvidia GPUs with 896MB or more RAM and does not support AMD/ATi GPUs at all).

[Hannu Korpinen]

I did measure some values for Vegas Pro 11.
My computer i7 920@3.97 12G ram and nVidian GTX480.


Rendering MainConcept AVC
Automatic for both cpu 80%, gpu 68%, 15sek
Only CPU used cpu 95%, gpu 5%, 54sek
Only GPU used cpu 6%, gpu 68%, 15sek

Same clip rendered Sony AVC
Automatic for both cpu 50%, gpu 26%, 24sek
Only CPU used cpu 60%, gpu 10%, 27sek
Only GPU used cpu 50%, gpu 27%, 24sek

Looks like MainConcept AVC uses GPU more efficient.
During preview gpu is running with 80% load.
Prosent values are from MSI Afterburner for gpu and task manager for cpu.

[Randall Leong]

Originally Posted by Hannu Korpinen

I did measure some values for Vegas Pro 11.
My computer i7 920@3.97 12G ram and nVidian GTX480.


Rendering MainConcept AVC
Automatic for both cpu 80%, gpu 68%, 15sek
Only CPU used cpu 95%, gpu 5%, 54sek
Only GPU used cpu 6%, gpu 68%, 15sek

Same clip rendered Sony AVC
Automatic for both cpu 50%, gpu 26%, 24sek
Only CPU used cpu 60%, gpu 10%, 27sek
Only GPU used cpu 50%, gpu 27%, 24sek

Looks like MainConcept AVC uses GPU more efficient.
During preview gpu is running with 80% load.
Prosent values are from MSI Afterburner for gpu and task manager for cpu.

Thanks for the results. It clearly shows that the CPU-only mode in the MainConcept AVC encoder leaves a lot to be desired (performance-wise) despite the very high CPU utilization. By contrast, the CPU-only mode in the Sony AVC encoder is fairly efficient; hence the barely detectable improvement in GPU mode.

[Jeff Harper]

GPU accleration really does offer some real improvement, it's a shame my GTX 460 actually slows things down.

Nice overclock on your 920, Hannu.

[Randall Leong]

Originally Posted by Jeff Harper

GPU accleration really does offer some real improvement, it's a shame my GTX 460 actually slows things down.

Yep. Your own tests proved that a good balance between CPU and GPU is important. After all, on a hexa-core i7-9xx Gulftown system such as yours, a weak GPU is definitely holding it back. Had your system been equipped with the new i7-3930K and an X79 motherboard, you would definitely need a GTX 570 or GTX 580 just to keep things in balance.

On the other hand, it is downright silly to go heavy on the GPU and light on the CPU, as the PPBM5 (for Adobe Premiere Pro CS5 and CS5.5) results of an i3-2100 system equipped with a GTX 480 showed: That system (at 16 seconds) scored a measly 1 second faster than my i3-2100 Internet system equipped with a GT 240 1GB GDDR5 card (17 seconds) in the MPE timeline render/export tests.

[Randall Leong]

Jeff,

I also forgot to mention that if the GPU that you choose is too old, too low-end and/or lacks sufficient VRAM, then not only would Vegas force CPU-only mode, but the performance in CPU-only mode would also be degraded (even compared to an otherwise identical system with a good higher-end and newer GPU but still running in CPU-only mode in Vegas). This is because system RAM is almost always slower than GPU VRAM to begin with. And the less VRAM the card has, the poorer the performance in Vegas.

[Jeff Harper]

My card is the GTX 460SE, and it's 1GB of DDR5 at 3400MHz with 288 cuda cores, and the minimum for Vegas, as I recall is under 200, I think.

I would like to get better performance, but some with better cards than mine are not getting anywhere with it either. I have the option to turn if on and off, and it's definitely better off, for whatever reason. Maybe the freq is too high on my card? It came overclocked so I don't know.

[Larry Reavis]

The main problem with GPU rendering in Vegas is that you're stuck with MainConcept AVC or similar low-quality AVC. That's why I always render to Sony .MXF or DNxHD, then put it into Handbrake. That way, I get a GOOD low-bitrate .MP4 file that I can put on YouTube or my website. You can see the results of 500kbs videos at Yogananda, fundamentalism, atheism: A journey toward self-realization. In my experiments, the quality from Handbrake is so much higher than that available from the codecs available in Vegas so that I don't mind the extra step.

I also render every clip first to Cineform before putting it onto the TL, and then render out a complete Cineform intermediate once I complete the project. GPU acceleration does not work for Cineform. For me, the GPU acceleration is a waste.

Instead, I put my money on a fast CPU. After getting by with an i7-940 for some months, I finally coughed up about $450 and got an i7-970 6-core chip. Popped the puppy in the MB and got instant gratification - just a few percent slower renders than an i7-980x, at half the cost. It runs fine at 4.2 gHz, but just to be safe and cool, I run it usually around 4 gHz.

As mentioned above, everything else on the computer runs faster too. I use a fast SSD for boot, and it's hard to want anything more in a computer. This one is fast, everything is working right in Win7-64, and it is 100% stable.

Bottom line, invest in a CPU if your MB allows. It is more flexible, and it will work GREAT even with 60fps progressive.

[Randall Leong]

Originally Posted by Larry Reavis

The main problem with GPU rendering in Vegas is that you're stuck with MainConcept AVC or similar low-quality AVC. That's why I always render to Sony .MXF or DNxHD, then put it into Handbrake. That way, I get a GOOD low-bitrate .MP4 file that I can put on YouTube or my website. You can see the results of 500kbs videos at Yogananda, fundamentalism, atheism: A journey toward self-realization. In my experiments, the quality from Handbrake is so much higher than that available from the codecs available in Vegas so that I don't mind the extra step.

I also render every clip first to Cineform before putting it onto the TL, and then render out a complete Cineform intermediate once I complete the project. GPU acceleration does not work for Cineform. For me, the GPU acceleration is a waste.

Instead, I put my money on a fast CPU. After getting by with an i7-940 for some months, I finally coughed up about $450 and got an i7-970 6-core chip. Popped the puppy in the MB and got instant gratification - just a few percent slower renders than an i7-980x, at half the cost. It runs fine at 4.2 gHz, but just to be safe and cool, I run it usually around 4 gHz.

As mentioned above, everything else on the computer runs faster too. I use a fast SSD for boot, and it's hard to want anything more in a computer. This one is fast, everything is working right in Win7-64, and it is 100% stable.

Bottom line, invest in a CPU if your MB allows. It is more flexible, and it will work GREAT even with 60fps progressive.

In addition, don't go too cheap (low-end, with TurboCache permanently enabled and can't be disabled at all whatsoever) or too old (with too little graphics card RAM) on the GPU for that upgraded system. Those older and/or low-end GPUs actually steal some of the system RAM because video editing and encoding eat up a very large amount of graphics RAM. As such, with older and/or slower cards, there will be a lot less system RAM available for Vegas or any other NLE to run efficiently. The result is much-slower-than-expected performance even with an extremely fast CPU -- and that's in CPU-only mode.

[Tom Roper]

I've been using Handbrake and Avid DNxHD to make beautiful web video, but the 1080/60p mp4's don't play on my PS3 so this limits usefulness to pc play only. I haven't found anything that will remux 1080/60p Handbrake mp4's into a PS3 playable .ts stream. I've tried TSmuxeR, TSremuX and Yamb.

The secret behind Handbrake is the award winning open source x.264 encoder. Handbrake itself is just a gui. My $0.02 about Vegas 11 PRO 64 bit is a tale of two pieces, the excellent editor and the rather ordinary rendering plugins. OpenCL and Cuda seem to improve the performance of the filter plugins and preview, but when it comes to rendering output, not as obvious. I suspect one reason for this is the local memory attached to the gpu card is probably less than the memory available to the system cpu.

The Sony AVC encoder in the 64 bit version is improved, but extremely limited in terms of the control you have with the settings compared to Handbrake x.264 which is a shame, but the 1080/60p AVC video it renders is easily muxed with Dolby AC3 5.1 audio into a PS3 playable .ts file for my home theater system.