Sony Vegas 10 Slow rendering CPU / GPU rending tested

[Davd Keator]

I spoke to an old Computer Engineer. He claims that RAM to the CPU is an incredible bottle neck in reality. The biggest issue is the lag between, the CPU calling the memory controller for the read, write, & VERRIFY… Apparently the Verify command is what’s slow, getting a confirmation that the file was read correctly, rendered, sent to ram, then sent off to the HD. the HD then sending back confirmation to send off to the next frame to be computed.

By utilizing RamDisk, all lag other than the inherent delays with in ram and its controller we seen. As stated, it didn’t matter having the swap/source/output on the same drive.

Now as the person stated previously the switch from dual to quad opened up all new issues. Well, if you are hitting the Windows swap file, then yes, performance TANKS. Just add more ram. 2 gigs per core then no swap file access needed EVER…. 64 BIT needed…

Hyper threads don’t count. It’s still the same core, just a thread on standby if there is a cache miss. This happens regularly on any CPU, just when doing millions of SIMPLE integer commands ‘RENDERING’ the que lag to switch threads is actually a performance hit in VEGAS. If the instructions to render were vastly more complex and each process took hundreds of computer cycles to calculate, then yes, HT would be beneficial. In conclusion, disable HT and you will see a performance increase…2 – 7% but it helps.

Now, I only have dual core, quad core, and now the 6 core cpu’s. All I have noted is that Vegas does not scale all too well after 4 cores. Perhaps, the code of Vegas needs multiples of 4, ie, 1-2-4-8-16…I’d love to test on a MAGNY CORE – AMD, I’m holding out for the new Bulldozer cores.

Good luck…

[John Dirickson]

Thanks, I’ll certainly check them out. I was looking for information on which brand would be the fastest to render. Premiere Pro is the only 64 bit program I believe while Vegas 10 Pro is 32 bit.

[Dave Haynie]

Hi… old computer engineer here (Google or Wikipedia “Dave Haynie” if you want a bio).

If you have an older CPU, you have a memory controller. Anything not covered in dust from AMD, or anything with “i” in the name of the CPU from Intel, and there’s no separate memory controller — memory is managed directly from the CPU.

For DRAM, there are read cycles and write cycles. No such thing as a verify cycle, NADA. Some PCs have parity or ECC (error check/correct) memory.. there’s about one extra cycle in there, usually. DRAM (eg, DDR, DDR2, DDR3 in most systems people still use… DDR == Double Data Rate, which means two data cycle for every clock cycle) is rarely any bottleneck.

Yeah, it’s technically much slower than your CPU. But it’s also several orders of magnitude faster than your hard drive. And particularly for video rendering, it’s not that much of an issue. Your CPU has several tiers of on-chip cache, which help out here. And they’re not tiny.. on my system, each of six cores has a 128K of L1 cache… that runs pretty much as fast as the CPU. That’s backed by 512K of L2 cache per core, which in turn is backed by a shared L3 cache (L = level). So basically, if the problem you’re working on fits in 9MB or so, the CPU never touches main memory.

Caches do other things too, though. Modern DRAM is called synchronous DRAM… a fancy way of saying it’s clocked. When you address a random memory location, that process can take 5-10 cycles, maybe more. But once you have that memory item you want, the next couple are practically free by comparison. So the CPU just grabs those, and stick ’em in the cache. Most CPUs these days have two 64-bit wide buses and run four or eight cycles for each access… so they grab memory in chunks of 256-512 bytes at a time, two a time.

The idea of a cache is local storage, like that big pile of papers on your desk that your S.O. probably thinks belong in the file cabinet. If the thing the CPU is after is already in the cache (for instance, the algorithm for encoding AVC), it doesn’t need main memory.

Then there’s writing back to main memory… modern CPUs do what they call “posted” writes. The CPU writes, and usually it appears to the CPU to take absolutely no time. That write goes into cache, and at some point later, finds its way to main memory.

When you do video encoding, there’s a pretty good chance you’ll be waiting on the CPU, and possibility you’ll be waiting on the hard drive. Main memory has very little effect — it’s part of the process, but just not a practical bottleneck in video work.

A RAM disk on a modern PC is usually a very bad idea. First of all, the modern OS is very efficient at buffering data in large blocks. This keeps HDDs reading and writing at full speed. One block to/from a hard drive is slow… a couple of megabytes or more at a time, and you’re hitting the 50MB/s-100MB/s the drive can handle. Add to that the fact that most of time, the video you’re reading and writing is fairly small… 25Mb/s for most camcorder video, 50-100Mb/s for higher-end video. Your hard drive is 15-30x faster, your memory is something on the order of 10,000x faster.

If a program runs low on memory, it’ll have to simulate memory using virtual memory. The OS tells the program it has the memory, and when it uses it, there’s a hardware trick via the memory mangement unit (MMU).. the CPU traps, a routine kicks some other resource out of memory temporarily, and then loads what you need into that freed memory. It works, but as you use more VM, your performance starts to favor that of the HDD rather than your DRAM. Bad move. A RAM disk was a decent idea when I worked on the Amiga computer back in the 1980s… when the alternative was floppies. Today, it’s probably going to slow you down, unless you have so much crazy DRAM you can map whole video files.

As for multi-core CPUs.. I have a 6-core processor, and I get 97-100% CPU utilization on rendering. I’d say that’s pretty good scaling. If you’re not seeing that, you have an I/O or memory problem somewhere… but it’s not memory speed. Could be a shortage, or maybe your HDDs are just too slow (and yeah, even a RAID can be too slow if you’re pulling too many files from it at one… but that’s a different performance problem).

As for hyperthreading…it’s a bit more sophisticated than just swapping on cache misses. But yeah, it’s not always a win. For one, you’re spreading the same caches across twice the work. That’s not as bad as it sounds if all threads are rendering, and the rendering algorithm fits in cache. But if it doesn’t, you’re far more likely to thrash the cache… maybe even just an L1 or L2 cache, but thrash you may. And of course, if there is a hard drive bottleneck, increasing the aggregate CPU performance is one way to expose that.

-Dave

[John Rofrano]

[John Dirickson] “Premiere Pro is the only 64 bit program I believe while Vegas 10 Pro is 32 bit.”

Correction… Vegas Pro was 64-bit two years BEFORE Premiere Pro! Sony has put out Vegas Pro 8.1, 9.0 and 10.0 ALL of which are 64-bit. Adobe is “catching up’ to Sony with 64-bit support (..and it took them long enough they missed an entire generation of 64-bit OS with no support i.e., Vista)

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Dave Lozinski]

Dave,

I never thought I’d be a reader and contributor to a group of forums to a well known computer super star.

You’re forever one of my heroes with the work you did on bringing what I still consider the best and most joyful line of computers — the Commodore Amiga — to the world.

That old phrase, “I love you man” is all I can say.

Would love to have your autograph and a photo op, but I suppose for now I’ll have to settle for your electronic signature. 🙂

-Dave

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https://www.davelozinski.com
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[Dave Haynie]

Hi-

It’s great to hear from someone who remembers the Jurassic era of personal computing. I’m not sure “well known computer super star” still applies, but I’m really proud of what we accomplished back in those days.

I did one film on the Amiga in the dark, dark days of analog, and that was my video about the end of Commodore. Things were getting bad, and I had recently seen Michael Moore’s “Roger and Me”, so I got motivated. With years of still photography, absolutely no video experience, and nothing but a “Video8” (not even Super) camcorder. And more embarrassing still, I used the built-in mic. But I did sell about 4,000 copies, not too shabby.

That was sophisticated I guess, for the day, for a garage production. I used Scala MM400 to control my camcorder via LANC and my JVC Super VHS deck via IR. I borrowed a SuperGen 2000 and a JVC TBCPlus, and managed to get them to fit into an Amiga 3000+ prototype (same Pandora/AA/AGA chipset as the Amiga 4000). Audio was though a small mixer… I just had to move faders and hit the cassette’s “play” button at the right time.

I started doing music, later video, on PCs. Particularly in the early days, PCs were just a mess. Since I actually had designed Amigas that could do the same jobs, I hung around the PC-DAW mailing list, helping folks get their PCs to actually manage to do recording (and sometimes, even MIDI) properly. One heated discussion actually landed me free copies of Vegas 1 and Acid 1… seems the guy I was defending (who was correct) worked at Sonic Foundry. Vegas Video came along just in time to save me from the hell that was Adobe Premiere and/or it’s drug-addled pool-boy, Ulead Media Studio Pro.

So now, between compiles and renders and autoroutes, I try to help out on boards like this.. as well as learning what I don’t know about video.

Oh, if you haven’t, and you’re an Amiga or C= fan, check out my “hazydave” channel on YouTube. I have some C= related stuff there, as well as a small number of other videos. If I actually manage some time off this Christmas, hopefully a couple more music videos…. I wrote a couple new songs last summer.

-Dave

[Rob Murtha]

Hi Dave, thanks for sharing – can you please post your 6 core configuration, it sounds like you have a winner. I’m considering an intel Xeon X5650 dual setup, 24GB ram SSD main drive sata iii / usb 3.0.

[Dave Haynie]

I’m running an AMDx6 1090T, six core, 3.2GHz, 8GB of DDR3 SDRAM at whatever the maximum supported speed on the AM3 socket is these days. No overclocking.

This is a relatively cheap six core system, and I have no doubt that a sufficiently clocked 3-bus Intel will clobber it on many things, even a 4-core on some things. Though AMD does better on most rendering than it does on as an overall average, factoring in games and the other usual benchmark stuff. And for the price of one Xeon X5650 I could have bought four 1090Ts, and had beer money left over. The 1090T is still commodity prices, while the Xeons and higher-end i7s are still in the “performance at any price” category.

The x6 wasn’t a planned upgrade. My Q9550 motherboard died one morning, and I had enough work to do that I had to fix it that day. But it’s never good to simply replace what you had, when an upgrade doesn’t cost much more. Thus, the x6, which is substantially faster at rendering (all I care about, when it comes to CPU performance) than the Q9550. So it was ~$400 (CPU, MB, memory) well spent.

-Dave

[Anders Salvesen]

Hey…

I just updated from sony vegas pro 9 to 10 to test the rumored gpu accelerated rendering, and as fas as i have experienced now is that sony vegas 10 is more slow than vegas 9, and the gpu rendering isnt much impressing.

I do in this moment render a full Hd video and the cpu is just at 60% of usage and gpu is only using 8% of the cuda engine, is that normal? or do i have the wrong settings?

cpu: intel core i5 quaad 760 2.8ghz @ 3.57
gpu: zotac gtx 460, core: 675mhz @ 830 aka cuda

With sony vegas i i used like 80-90% of cpu usage…

[John Rofrano]

[anders salvesen] “I do in this moment render a full Hd video and the cpu is just at 60% of usage and gpu is only using 8% of the cuda engine, is that normal? or do i have the wrong settings?”

This is what a lot of people are seeing. I don’t think that this working properly yet because no one has seen a significant boost in performance with the GPU and has you have seen, it’s not really using the GPU much.

~jr

http://www.johnrofrano.com
http://www.vasst.com