PLEASE HELP DIVX on Pentium 4!!!

[legendvr]

How do you get decent frame rate in FlaskMpeg (I use preview 0.6) on a Pentium 4?
I have an Athlon 1600+ machine and that thing gets 16 fps (slowest/ with audio mp3 encoding without much tweaks).
I just got a P4 2.0 (northwood) 333 DDR machine and I get 14 fps during identical encoding.... I've tried SSE2 idcts and it doesn't get any better...

What am I doing wrong? Or is is P4 just not that great for DIVX?

Thanks.

[khp]

Check the memory latency settings on the P4. But at best the P4 should only preforum slightly better than the Athlon.

[legendvr]

Thanks for suggestions.
Memory is CAS2 set to 2-6-2-2-2-1.
Can you please tell me what idct am I supposed to be using?

khp, what's your setup and how many fps do you get?

Thanks.

[khp]

Originally posted by legendvr

Can you please tell me what idct am I supposed to be using?


I think SSE2 is the best one for the P4.

Originally posted by legendvr

khp, what's your setup and how many fps do you get?


I usually get 20-25 fps with an Athlon XP1700 using GKnot with divx5.

[legendvr]

That's very good frame rate.
What size of the frame do you use and do you handle the audio at the same time?

[Enchanter]

That really depends on the type of video you are working on as well. I usually get 25-30fps for PAL materials (640x352) on my P4 1.8GHz (Willamette). However, on NTSC materials (same resolution as above), the speed gets cut down to 12-17fps due to the required decombing procedure.

I handle my audio separately, but what you'll be seeing Flask display (in fps) is the true video processing rate. When it is processing audio, you'll find that it pauses the 'meter reading.'

[legendvr]

Thanks Enchanter.
The frame rates I quoted were for exactly same job.
I always keep the original size of the movie when encoding (just looks better to me).
Could you please tell me if you have to download any P4 specific optimizations to make the P4 peform well?!
As far as I understand, the only way to get P4 do well in any type of encoding is to tap it's SSE2 units because it's lowly x87 FPU is pretty slow.

Also it appears that P4 is very sensitive to memory bandwidth (P4 with 333MHzDDR does A LOT better than with 266MHzDDR) whereas Athlon is relatively insensitive as far DIVX encoding is concerned. Am I wrong?

[Enchanter]

I'm not aware of any significant speed improvement when I tried SSE2 optimisation on Flask 0.6 on my P4. I'd be more inclined to say that changing to a faster encoding procedure (eg. Avisynth + Virtual/nandub) will DEFINITELY yield a speed plus quality gain. Pretty much the reason why I moved away from Flask almost a year ago.

Also it appears that P4 is very sensitive to memory bandwidth (P4 with 333MHzDDR does A LOT better than with 266MHzDDR) whereas Athlon is relatively insensitive as far DIVX encoding is concerned. Am I wrong?
Strange. I have the SIS645 chipset that supports DDR333 memory. I changed my RAM modules from 266MHz to 333MHz half a year ago and I only noticed about 1-2fps in speed. What made it worse was that system stability became an issue and I spent many days tweaking the board before it would work stably again (there is a full story of it under the Off-topic section, if you're interested). Anyway, that was the fault of my chipset, not the memory. ;) Maybe you have a better speed gain than me.

[legendvr]

Those are all excellent suggestion. Thanks, Enchanter.
I admit that I'm pretty ignorant as far actual field experience with P4s is concerned... as I mainly deal with Athlon/ PIII machines.

I'm was actually planning to spend a chunk of time this holiday season learning and tweaking encoding with Virtualdub... I'm just getting ready to build a new gaming/ Divxing rig, so I'm trying to choose AMD vs. Intel. Unlocked T-bred B running at 400 FSB with NForce2 Dual DDR sounds pretty tempting...

I'll run some more tests and report.

BTW, how is the SIS chipset working out for you?

I have a few AMD 745 rigs running very well... but don't know about their Intel stuff all that much.

[Enchanter]

Thanks for the compliment. ;)

BTW, how is the SIS chipset working out for you?
It's working fast and stably for me now, though I wish it would work like that straight out of the box. :( Apparently I bought a first version of the chipset and hence the flaky DDR 333 support. I'm planning to upgrade the system in hopefully one year's time and I may go with either AMD or P4, depending on my financial and market conditions. ;) Above all, I think I will hold onto my DDR333 module since I bought at a not-so-cheap price.

Do report your findings though. I've not paid much attention to the CPU market anyway, so some fresh news would be welcome.

[MrSnail]

I'm planning on upgrading my Athlon 900 256MB PC133 to something like an AMD XP 2100 512MB 2700DDR and wondered whether it would speed up my DivX encoding by much.

Also i have a 120GB ATA100 drive and a 60GB ATA100 drive and wondered whether having a RAID level 0 would speed up encoding, although now thinking about it, it encodes at nowhere near those rates so I guess RAID wouldn't make any difference :confused:

Thanks :)

[khp]

I'm planning on upgrading my Athlon 900 256MB PC133 to something like an AMD XP 2100 512MB 2700DDR and wondered whether it would speed up my DivX encoding by much.

Yes, you should get close to twice the encoding speed, from an upgrade like that.

Also i have a 120GB ATA100 drive and a 60GB ATA100 drive and wondered whether having a RAID level 0 would speed up encoding, although now thinking about it,

No, for DVD->Divx conversion raid will make next to no difference, it might actually reduce the encoding speed, because of the increased complexity, of mergeing/splitting the striped data. The only place in Video coding where raid migth be of any use, is uncompressed TV captures.

[Enchanter]

AMD XP 2100 512MB 2700DDR
Since the older XP 2100 uses a FSB of 266 MHz only, why not consider getting the slower and cheaper DDR 266 (PC2100)? You won't see any benefit on using PC2700 module since the chip won't take advantage of the extra memory bandwith.

[MrSnail]

Originally posted by khp
Yes, you should get close to twice the encoding speed, from an upgrade like that.

Sounds good to me :)

Originally posted by Enchanter
Since the older XP 2100 uses a FSB of 266 MHz only, why not consider getting the slower and cheaper DDR 266 (PC2100)? You won't see any benefit on using PC2700 module since the chip won't take advantage of the extra memory bandwith.

Ah right - that explains the big price jump once you get over the XP 2100+ :)

Maybe I'll save a bit more and go for a better processor - I'm beggining to feel this computer get slower and slower :D

[Enchanter]

The XP 2200+ would be of better value to you. Or you could consider the P4 2.53GHz, which is the sweet spot for P4 purchases now (and yes, it will take advantage of PC2700 modules provided you use a motherboard that supports the memory).

[HDRed]

Actually you can run a 266mhz fsb processor asynchronous to the memory speed and still see a gain in performance.

I.E. - PC2700 DDR on a 266mhz athlonxp will still be faster than PC2100 DDR, even though the fsb/mem is async.

The 2.53Ghz P4 runs on a 533mhz fsb (133mhz). So to run PC2700 memory would be to use a 4:5 memory divider which would still be async - you're contradicting yourself on the fsb issue, because a 133mhz p4 runs sync with PC2100 DDR, not PC2700.

Get an athlonxp 266mhz and use pc2700 memory.

[Enchanter]

I.E. - PC2700 DDR on a 266mhz athlonxp will still be faster than PC2100 DDR, even though the fsb/mem is async
I don't own an Athlon, but I have read conflicting reports from others. Given that they really know their stuff (and they're respectably knowledgable and pretty hardcore at it), you will understand that I trust their sources more.

The 2.53Ghz P4 runs on a 533mhz fsb (133mhz). So to run PC2700 memory would be to use a 4:5 memory divider which would still be async - you're contradicting yourself on the fsb issue, because a 133mhz p4 runs sync with PC2100 DDR, not PC2700.
I have to disagree with that. The quad-pumped 533MHz-FSB (it's FSB is NOT 133MHz) P4 requires an optimal memory bandwith provided by a 533MHz memory. The PC2700 (aka 2x166MHz) does not even provide close to 75% of the required memory. Even the PC3200 (aka 2x200MHz) does not. RDRAM possess the bandwith required by P4 chips (dual-channel 800 & 1066), but unfortunately, it's price isn't the most budget-friendly around and its memory latency does not match that of DDR.

Get an athlonxp 266mhz and use pc2700 memory
Correct me if I'm wrong. To be able to utilise the extra bandwith of PC2700 memory with the 266MHz-FSB Athlon, this would require overclocking via the FSB, does not it?

[HDRed]

Correct me if I'm wrong. To be able to utilise the extra bandwith of PC2700 memory with the 266MHz-FSB Athlon, this would require overclocking via the FSB, does not it?
No, it doesn't require overclocking the FSB. Only on the newer nForce2 boards does running the memory async yield lower performance than running it sync.

You're thinking of memory bandwidth here, and while the 266mhz fsb will not utilize as much of the bandwidth provided by the pc2700 speeds, it will certainly utilize enough of it to make it faster than pc2100.

PC2700 is better on a 266mhz fsb than PC2100 because higher frequency means lower latency. In other words, the memory is faster at caching the data being sent to the cpu because of the higher speed = lower latency phenomenon. PC2700 is noticably faster (check the benchmarks, don't take my word for it) than PC2100 on a 266mhz frontside bus IF you are not using an nForce2 motherboard.

Also, as far as the RDRAM for the P4 comment - that's irrelevant. We're talking about PC2100 vs. PC2700 memory here, not RDRAM. Of course RDRAM is the best choice for the P4, but that has nothing to do with this gentleman's dilemma.

[chickeneater]

Of course RDRAM is the best choice for the P4, but that has nothing to do with this gentleman's dilemma.
not exeactly true, recently in the PCWORLD magazine, the benchmark test showed that DDR actually performed better on the P4 than RAMBUS on the P4...in which case after reading that article, we got DDR for our computer

[Enchanter]

Originally posted by chickeneater
not exeactly true, recently in the PCWORLD magazine, the benchmark test showed that DDR actually performed better on the P4 than RAMBUS on the P4...in which case after reading that article, we got DDR for our computer
A little correction. RDRAM-based systems remain unbeatable when compared against DDR systems.

However, the more recent chipsets (Intel e7205, to be more specific) that use Dual-channel DDR-RAM have been found to outperform RDRAM-based systems at a fraction of the cost.