8.0c vs 8.1 rendering speed

Terje wrote on 10/3/2008, 2:43 PM

Think of 8c as a truck with a 1 ton capacity and 8.1 as a truck with a three ton capacity.

This is not an analogy at all. There is nothing inherently faster in 64 bit computing than in 32 bit computing (or 8 or 16 bit for that matter) unless you have operations that require or benefit from the larger registry size or that needs more than 2G of contiguous memory. There are a few other operations that will benefit, but not that significantly. There is no reason whatsoever to think that a 64 bit computer will have a significant speed advantage. In fact, in very many cases, a 64 bit computer will be slower than a 32 bit computer for a variety of reasons (all other things held constant). This includes things like getting instructions (that are twice the size) from memory might be slower on a 64 bit computer than a 32 bit computer.

The only real benefit of 64 bit computing comes in accessing more RAM. In other words, if your task requires, or can benefit from, keeping huge amounts of data in memory, you will see a speed improvement with 64 bits. For video editing that might mean that there is no speed improvement whatsoever (but hang on for two seconds before killing me). The reason is that video editing is in most cases CPU bound, not a memory hogging problem. For example, if you encode SD or HD video to H.264 the computer is going to spend so much time encoding the data in memory (that is, running math calculations on it) that the time it spends getting new data from disk is irrelevant. In such a scenario there is no real benefit at all to 64 bits.

Now, to the part where there is a difference. If the encoding process, and that might really be the case with color correction or filters etc, uses a lot of 64 bit math, then you should see an improvement, but that would depend entirely on what the encoding process entailed.

Terje wrote on 10/3/2008, 2:48 PM

The ONLY way to pump more speed from 8.1 is to use 8 cores, then you could achieve about double rendering speed compared to 8.0c, that can only run on 4 cores.

Absolutely not on all points. There is no way that 8 cores will yield twice the rendering speed of 4 cores. None whatsoever. If 8 cores is to run at twice the speed of 4 it would mean that you were able to perfectly divide a task into 8 identically complicated pieces and that there would be no interference and no scheduling overhead. That is never going to happen. Also, the more cores you add the more overhead the scheduling will require and the less speed gain you will see.

The other point here is that 32 bit Vegas can only access 4 cores. I have never heard this and quite frankly it would surprise me mightily if that was the case. There is no reason that there would be such a limitation. There is nothing in the 32 bit world that would prevent you from running more than 4 threads. I have 32 bit software that has hundreds of threads.

srode wrote on 10/3/2008, 3:52 PM

'"Here's an analogy for you. Think of 8c as a truck with a 1 ton capacity and 8.1 as a truck with a three ton capacity. Which one will get a two ton load across town faster?

Rob"

A Better Analogy would be:

Two pickup trucks empty 1 gas and one diesel - in a race the gas truck might win - load them up with a ton and race again - the diesel wins - loaded up 8.1 will out run 8.0c - with a light load it may not.

rmack350 wrote on 10/3/2008, 6:30 PM

Sigh! All I'm talking about is the capacity to use more memory and not have to keep going back the the page file. Sorry if that was confusing.

Rob

rmack350 wrote on 10/3/2008, 10:09 PM

Similar idea, yes. Anyway, the general idea here is that when 8.1 is tested with a very demanding project it does well, when it's tested with a relatively easy job it'd not quite as fast as the 32-bit version of Vegas.

My premise was that this is because 8.1 can use more physical RAM (more junk in the trunk) and that even if it has to use virtual memory it doesn't necessarily run out of memory. There's no 2GB virtual space limit.

The important questions:
-What's the advantage?
-Is it really faster?
-Will it allow me to render a project that 8c stalls out on?

It sounds like the advantage is that it can finish a memory intensive project where 8c can't. In that situation it's infinitely faster than 8c. And in projects where 8c seems memory starved 8.1 is much faster.

It doesn't sound like it's inherently faster because it's a 64-bit application nor does it sound like it's faster because it can use 8 rendering threads (and yes, Terje, Vegas uses a LOT more than 8 threads to run but people are talking about rendering threads-something you can set in prefs). Maybe I'm wrong about that but I haven't seen those posts yet.

The down side is that almost no third party plugins work with 8.1 and that can put you in a situation where you can't use it at all.

Rob Mack

Terje wrote on 10/3/2008, 11:17 PM

All I'm talking about is the capacity to use more memory and not have to keep going back the the page file.

Then your analogy should have been: Imagine two one-ton trucks. Both having to get the same amount of stuff. Both taking it to the same place. Some times one of the trucks might have to go a little further to get his load. Then, in those cases, if and when they occur, one truck might make the total job faster.

Your analogy would imply that 64 bits and access to more memory is faster than 32 bits and 2G limits generally, and that is only true if the application in question needs access to more than 2G of memory. A video application may or may not benefit from access to large amounts of contiguous memory. The encoding process being the slowest, often will not need, or be able to use, the extra memory.

Terje wrote on 10/3/2008, 11:21 PM

this is because 8.1 can use more physical RAM (more junk in the trunk)

and again, just to be clear, that assumes that the application needs a full trunk, or can make use of a full trunk. Assume you have an SD project that you are encoding to MPEG-2 with a lot of color correction, effects and everything, a 32 bit application can easily keep all the required data in memory at once (2G is plenty) and there will be no real benefit (everything else held constant) to 64 bits. The task of moving data into memory is going to be an insignificant portion of the overall work load. It is the data manipulation that takes time, and that is CPU time only.

rmack350 wrote on 10/4/2008, 8:43 AM

I think that was a given, but thanks for clarifying and expanding on my point.

Rob

rmack350 wrote on 10/4/2008, 9:28 AM

Exactly, and that's why 8.1 shows no improvement (or worse) on those sorts of projects. You're illustrating the other side of my point which is that 8.1 doesn't bring much to the table for projects with low or modest memory needs.

I'm kind of wondering if this sort of memory consumption couldn't have been taken care of with smarter coding, but SCS started down the 64-bit road several years ago and I suspect they had to make a business case internally to do this. I have to assume that the writing was on the wall even then.

Rob

lefty51 wrote on 10/4/2008, 5:30 PM

by default the threads are set at sixteen, I have reduced it to eight and will try that. now I keep getting an error message when I start 8.1 in vista BUT not xp. After reading some of these post I think it might be the sony PMB program that comes with the sony camcorder, yet it works okay on XP. I am about to give up on vista.. sound familiar ?

megabit wrote on 10/5/2008, 4:10 AM

Just a small contribution to the memory management (and hence - speed) differences between the 8.0c and 8.1: I just rendered a short (6 mins) piece into a format I use rather rarely, 1280x720p/25 WMV with two-pass VBR at the medium rate of 5Mbps.

The 8.0c did the rendering in one second chunks (I could see how it stopped for more than half a second after every 25 frames; it was in sync with the CPU load fluctuations). After the second pass, Vegas made an exception and died.

I rerun the rendering in 8.1, and the same job was done almost twice as fast, and the CPU load was an almost constant 98-100%. No crash.

The material rendered was nothing special at all - my usual 1080p/25 EX1 HQ stuff, with some dissolves, a single FX, and a single audio track.

Now, how is that to the "truck" analogy?

Himanshu wrote on 10/5/2008, 7:21 AM

megabit said:
The 8.0c did the rendering in one second chunks (I could see how it stopped for more than half a second after every 25 frames; it was in sync with the CPU load fluctuations). After the second pass, Vegas made an exception and died.

Megabit,

I've experienced a similar situation in my Vista64 SP1 system (Intel Q9450) as well. However the issue with that was too little RAM - I was running with 2GB and Vista was already using up gobs of it (I haven't tuned my system yet). I was seeing the rendering stop every 2-3 secs, followed by disk activity. Vegas 8.0c told me that to render the 65 mins of DV to MPEG2 would take more than 1hr on the quad core! BTW, no external disks involved, data was on an internal SATA drive.

I shut the system down, installed 2GB more to bring the total to 4GB, and restarted the render. This time the render did not stall every few seconds, disk activity was lower, and the render completed in 22 mins or so.

Granted, this isn't a comparison of 8.0c to 8.1, and even if anecdotal, this experience seemed relevant. When I have some more time I'll install 8.1 and see if/how that changes things.

rmack350 wrote on 10/5/2008, 10:02 AM

It parallels the truck capacity analogy but on the tonka truck scale. 8c had to make many small trips, 8.1 seemed to be able to keep itself occupied. Certainly not exactly the same as my truck analogy, though, because I was pretty much thinking about total memory requirements rather than how 8.1 would deal with small chunks.

It doesn't pay to work an analogy too hard. An elephant is only like a giant grey cow with mouse ears and a snake for a nose until you actually get to see a real elephant.

Rob

megabit wrote on 10/5/2008, 12:15 PM

Well, guys - to make things even a bit more complicated, I repeated my experiment, this time watching closely both renders (by the 8.0c and by the 8.1, of course run one after the other - not in parallel), and have noticed that BOTH did render by 25 frames chunks - but only at the second pass!

Now when you think of it, it becomes obvious that having already the output file ready, the second pass was optimizing it rather than rendering the timeline from scratch - hence the CPU activity for the entire GOP, alternated with reading the next portion (1 sec worth) from the disk.

And yet, the 8.1 did the whole job (i.e. the two-pass render) in about 40% less time than the 8.0c.

Himanshu:

I have 8 GB of RAM, so the 8.1 could benefit from what the 8.0c couldn't even address. I'm sure that if I had two quads rather than one, the difference would be even more pronounced.

Rob:

When I remarked about your analogy being "poor", I never wanted to disregard your way of thinking, or show mine is more "knowledgeable" in any way. I simply meant that real life scenarios/projects may be so different, that an analogy like that is a bit too simplistic.

rmack350 wrote on 10/5/2008, 3:26 PM

I don't mind. An analogy is a simplification.

I'd love to see some comparisons of dual quads vs single quads.

It certainly seems like memory use/availability is a a big factor. It'd be interesting to know why but most users just need a recipe, not the chemistry. They need to know where 8.1 shines and where it is lackluster, how they can benefit from it and whether they should even bother.

Of course everyone's also interested in what would make a good system for 8.1. Would dual quads be better? Would 8GB be better than 4? Is one version of Windows better than another? I notice in one of Himanshu's links that the different versions of Vista64 support different amounts of memory.

In the end, probably the most helpful thing is to hear examples of what people can finish. Could Darren Powell render that feature with 8.1? Can users do something with 8.1 that they couldn't do before (like render where no render has gone before)?

Rob Mack

Stuart Robinson wrote on 10/5/2008, 5:43 PM

For what it's worth, 8.1 isn't all about rendering speed, I've found it's far faster just on mundane tasks. For example, for me previewing 1080p is choppy in everything but draft mode in 8.0c, whereas 8.1 is fluid even in the best/full preview mode.

tcbetka wrote on 10/5/2008, 7:57 PM

I thought the truck analogy was a good one, actually...

This week I am going to install Vista 64-bit Home Premium onto an empty 80GB hard drive I have in my machine. It never worked, and tonight I trouble-shot the problem, and it appears to be a partially bad SATA cable apparently. Weird... Anyway, I have opted to go with Vista instead of XP--simply in case of problems with 8.1 that may require assistance from SCS. I also saw where somebody on these forums mentioned that the 64-bit version of Vista was significantly better than the 32-bit version. So I'll try it.

I will also install another 4gb of RAM for a total of 8gb. Then I'll install version 8.1 and give it a shot on the quad core intel.

TB

Mikey QACTV7 wrote on 10/6/2008, 11:17 AM

Well, I have yet to see 8.1 render without crashing. Is anyone rendering to a MT2 file.
I have a dell running 2 quads and 64 gigs of ram. I set the ram preview in vegas 8.1 at 6 gigs. My OS is vista ultimate 64. If you guys are getting it to work I am wandering if I need to do something on my end to get it to work. I was going to wait for the next update but maybe I need to do more looking and poking. I have uploaded sp1 for vista any other ideas?

Mikey QACTV7 wrote on 10/6/2008, 11:52 AM

Well, I got the 8.1 to render but it is going at a sloooow pace. The 8.0c on the same machine is flying. I am rendering 1080 mov files to hdv 720 m2t files. Sounds like my dell is running backwards? Any ideas?

cliff_622 wrote on 10/6/2008, 2:04 PM

"I have a dell running 2 quads and 64 gigs of ram. I set the ram preview in vegas 8.1 at 6 gigs."

The problem is not Vegas C,...it's your PC.

Take out 1 Quad CPU, disable multithreading in the BIOS and drop you RAM to 3 gigs.

If the moon, stars and sun are all alignment, your project should render fine. Oh,...dont forget tor drop your preview resolution to "draft" + "quater" just before rendering. This helps to compensate for the curvature of the Earth. (which known to cause problems with AVCHD file sometime)

CT ; - )

lefty51 wrote on 10/7/2008, 6:42 PM

Mikey, I too am running 2 quads and had the same result 8.0c was faster than 8.1. I have adual boot with xp64 and vista64.both versions were faster in xp than vista. what I did was tried different thread settings in both versions. by default 8.1 was set at 16 threads, 8.0c at 8 threads. rendering a10 min avi file (sd) that required recompression took 8:06 min at 16 threads and got quicker, down to 5:17 min with 2 threads. I can render a 1:06:26 avi file not needing recompression in as little as 5:19 min. They say that you should not have more threads than the amount of cores but less seems to be better. And vista is now quicker than xp. I have not turned threading or multi cores off as that seems counter productive to having the quads. So much for more is better

neilslade wrote on 10/11/2008, 3:35 PM

John Cline--

What happened to your original posts at
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=608377

with the test avi?

Thanks- Neil

By the way-- so what's your recommendation here-- Vista 64? I've got XP32 and everything seems to be fine-- a lot of work to change the OS or create a dual boot
quad 9750 CPU , 4GB ram, gigabyte board (new)

John_Cline wrote on 10/11/2008, 8:48 PM

Neil,

I wasn't participating in the thread to which you referred. Are you talking about this thread?

http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=601677

John

neilslade wrote on 10/11/2008, 11:03 PM

yeah-- boy, I am getting lost here--

anyway, a friend of my really suggested going to Vista at this point-- I've been running XP with no problems-- what do you think? He says coming into work where the machines are still XP seems so slow by comparison... I dunno.......... yes I'm aware of the memory requirements--- again, I'm quad core, 4GB ram---- but a million programs, many of which will require XP simulation and surely won't have Vista tweaks...