Bus Speed

[dopeskills]

I was wondering how important bus/memory speed is when divx enconding.

I'm currently using a P4 2.4Ghz with 512mb DDR266

Would there be a signifigant gain if I was using 533mhz RDRAM or dual channel DDR?

[jeremymacmull]

Hey there,

the answer to your question is no not particularily since divx encoding is primarily CPU dependant and as long as you have 256 mb or above its more than enough. As you already have 512 this would make no significant difference to DivX encoding.

EG in my system with 256 mb VDUB uses only about 40-60mb or ram and all my thing running while encoding etc in W2K use total about 170mb of ram. So i dont need more ram for that as for speed again its mainly CPU dependant as no machine can encode fast enough to need the extra speed that DDR2 ram etc would give

Hope this helps

Jeremy

[ppera2]

Memory speed is very important for encoding. Almost so much as CPU speed.

For example 50% faster CPU clock with same memory speed will gain max 25-30% in encoding speed.

256 MB fast memory is better for speed than 512 MB slower.

[theReal]

I think especially for a P4, high RAM speed is essential. Also for video encoding, there's a lot of data passed through memory and CPU, so slower RAM will make your CPU waste cycles (while Task Manager will still show that 100% CPU is used - it just waits with a high processor usage...).

When you asked me if I rather had 10MHz more RAM speed and 100MHz more CPU speed, or 30 MHz more RAM speed and nothing for the CPU, I'd take the 30MHz RAM speed without even thinking about it!

[asifanwar]

I encode full DVD resolution, with no filters or resizing, using DVD2AVI, AVIsynth, CCE2.66.07.
Here are the speeds of my last few machines:

Dual Athlon 1600 MP, with 512 Mb PC2100 DDR: 1.6x
Dual Athlon 2200 MP, with 512 Mb PC2100 DDR: 1.8x

Single Pentium4 2.4GHz o/c to 2.61GHz, with 512Mb PC1066 RAMBUS o/c to PC1160: 2.8x

The actual raw processing power of the dual machines was higher than the single P4, but the opening up of the data bandwidth has made a HUGE difference in encoding. I do believe that memory bandwidth is a key component in this hobby, as my Athlons were being crippled by stinky DDR (even dual channel DDR cant match my RAMBUS yet so I am sitting tight for now)

Hope this helps.

[Ramirez]

Originally posted by asifanwar
(even dual channel DDR cant match my RAMBUS yet so I am sitting tight for now)
Hmmm...512Mb PC2100 DDR vs.512Mb PC1066 RAMBUS,I wouldn’t call it fair Comparison,
you need to have the right hardware to make such a comparison. Have a look at
this (http://www17.tomshardware.com/mainboard/20021125/intel_granitebay-15.html) page and see how well the "stinky DDR" performs under correct conditions.
(Don’t get me wrong though,afaik RDR its still an unbeatable Performer.)

[dopeskills]

Interesting...

I'd like to upgrade to a dual channel DDR motherboard, but they seem to be a little too pricey and short on supply. I haven't been able to find one for less than $250.