for encoding/decoding does cache make much difference

[eddie123]

would there be much difference in encoding speed between say, a duron 1.6 and an XP1900+? Do these calculations rely on the processor cache much?

[jggimi]

Cache is very fast memory that is very close to the CPU. Cache can contain both program and data, and given the processing intensive, iterative nature of video filtering and encoding, and everything else being equal, I would expect you would see advantages with larger caches over smaller caches.

Moving this thread to the more appropriate PC Hardware/Software forum.

[Tuning]

I think larger cache produces better performance.So as for encoding jobs.When intel P4 was launched the L2 cache was only 256kb,but with speeds greater than 1.7Ghz(donno correct value)they have included 512kb L2 cache memory.Thus this step must have taken for better overall system performance.

;) - Tuning

[EagleDM]

I already made a test using a sample from my own DVD Starwars Episode I DivX 5.1.1 BETA1 with Quality Based Quant=2 Psy-Fast -No Profiles - B-Frames.


The resolution was 704x288 and I made a Test on the following machines

AthlonXP (Barton) working at 2370Mhz on Asus A7N8X Deluxe with 768Mb RAM at 215FSB

Pentium 4 - 3.2 (512k L2) HT on Intel 875 with 1Ghz Kingston HyperX (working at 800Mhz)


Pentium 4 - 3.2 (512k L2 + 2Mb L3) HT on Intel 875 with 1Ghz Kingston HyperX (working at 800Mhz)


the Pentium 4 Extreme Edition (with extra 2Mb of L3) had finished the video in less time than the other 2 systems... but not for soo much.


If you like to see the graphs and all... just check my page (i'm the hardware writer on it)

www.maximopc.org


and the review is at:

http://www.maximopc.org/showreview.php?id=72


the whole page and review is in spanish (i live in argentina) you could use some translator, but if you want to just look at the graphs, don't worry, they are all in english.


See it for yourself.


Eagle

[Mole]

A lot of benchmarks has shown that the CPU cache plays a very insignificant role when it comes to DivX/MPEG encoding.

This is because the CPU is constantly fed a huge amount of data to process.

Since the XP1900+ is also clocked at 1.6 GHz, you'll hardly notice any difference when encoding.

But in normal usage, the performance will be quite better.

[vinkes]

Originally posted by Mole
A lot of benchmarks has shown that the CPU cache plays a very insignificant role when it comes to DivX/MPEG encoding.

This is because the CPU is constantly fed a huge amount of data to process.

Since the XP1900+ is also clocked at 1.6 GHz, you'll hardly notice any difference when encoding.

But in normal usage, the performance will be quite better.

I concur, I've got a duron 1600mhz and a athlon 1800mhz. If I equal speeds by changing multipliers, the encoding difference 2-5%. So I wouldn't worry about cache. With divx encoding fsb speeds are much more important.

[colordog]

The extra cache on the P4 extreme is a waste of money if you're getting it for encoding.

Check out the links I posted in this thread last month:
http://forum.doom9.org/showthread.php?s=&threadid=64435

[Mole]

The P4 EE is a waste of money period.