Hey guys. I was just wondering if the speed of one's memory is a very crucial factor in Houdini. I often find myself blasting up the polygon count in my scenes, by copy SOPing a complicated L-system or something like that. I notice that the RAM gets chewed away fast when Houdini tries to solve these problems, so I thought that maybe RAM speed could be a critical element in the overall speed of one of these complicated solutions.
I wonder this because I will be building a new system soon (as we all are,) and I wondered if that really pricey DDR3 upwards of 1333Mhz was worth my time/money. otherwise I'm just going to get an butt-load of DDR2 fully buffered for a server board that can hold full 64bit OS amounts.
Everyone take care, and don't forget to copy SOP those L-systems!
-D

Memory intensive, CPU light tasks are generally the ones restricted by memory bandwidth (compositing, for example). In other cases, like SOPs, it plays a role but is not generally a big factor. With Houdini and a 64b OS, if I had to choose, I'd take more memory over faster memory.

Also, with every new DDR generation, equivalently-clocked memory is slower (so 1333MHz DDR2 is faster than 1333MHz DDR3). DDR3 is also a bit more expensive right now, so unless you're considering future proofing (which is really hit or miss) or already have a DDR3 motherboard, you may be better off with higher speed DDR2.

Note that even if you buy memory rated for 1333MHz, you have to be running your bus at that speed as well. If your FSB speed is 1066 or 800, you'll either have to change the memory divider to 5/4 or 3/2 in the BIOS, or the closest you can get to 1333MHz. The DDR2 memory with higher clockspeeds is generally for overclockers, and you don't gain much if you don't push it to its rated speed (though its latencies may be lower, improving performance a touch; but at double the price that's not a lot).

Finally, fully-buffered memory is usually one to two speed grades off the top-of-the-line memory but is more stable. It's also the only type of memory that can be used with Intel Xeons currently. Whether you need that extra insurance for a workstation is up for debate, but if you want 2 Quad CPUs in a box, you have to use 'em because only server boards will allow 2 quads, and they only take FB-DIMMS.

Then going with more memory is the plan of action! Thank you so much for your informative and thoughtful reply.

This article just appeared on Tom's Hardware. The link below takes you to the conclusion, figured most people wouldn't want to read 15 pages:

http://www.tomshardware.com/2008/04/09/toms_ultimate_ram_speed_tests/page15.html [tomshardware.com]

There is about a 1-3% difference between normal & high speed mem, unless you're doing Divx or WinAR, you get 7%. Woo… hoo. So, spend your money elsewhere…

I saw that one also. Thanks for the heads up.