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View Full Version : Ram configuration and Xeon Cooling recommendation request


morph166955
28th March 2007, 01:28
as some know I'm ordering out a new system to do high speed x264 encoding that is going to utilize 2x Intel E5345 2.33GHz Quad-Core Xeon's and 4GB of ram. I've ordered the case, motherboard and drives however I'm having a hard time making a decision on two things.

First, the ram. I have 12 DDR2 667 FB-DIMM slots (its an asus DSBF-D12 motherboard) that I can use. The motherboard is capable of four channel access to the ram. The question is do i go with 4x 1GB sticks of ram or 8x 512MB sticks? price wise its $2 more to go with the 512 so thats not much of an incentive there. Will having the 8 sticks work faster/more efficiently or will it cause a speed problem on the bus in some way because there are so many sticks?

Secondly, processor cooling. I have the option of either a 1U active or 2U passive for the processor (same chip, different fan/heatsync i guess). How hot are these things going to run if their pegged doing an encode on both? The case is a 2U rackmount from antec however its not going to be in an actual rack for a while, it will eventually but lets not put that into consideration at this point cause its a while away. Any cooling system I get has to fit the 2U profile and I have found only a few that meet this criteria. There are several large fans in the case blowing air directly over the cpu's so would two passive coolers do the trick for me?

I have to order this stuff in the next 24 hours that way its on site when i go to build it next week so I'm looking for any insights into either of these category's from anyone who has similar components and/or knows more about their operation then I do. Thanks!

jeffy
28th March 2007, 13:27
"the FB-DIMM run really really hot, system is running 8 sticks of 1G, and it will freeze when no air-duct installed. the air-duct is great design in this case." (TT Armor)
http://forums.2cpu.com/showthread.php?t=79148&page=9

Quad-Channel vs. Dual Channel comparison - the two tables at the end of the article
http://www.anandtech.com/showdoc.aspx?i=2816&p=11
http://www.anandtech.com/showdoc.aspx?i=2816&p=12
(thanks to: http://setiathome.berkeley.edu/forum_thread.php?id=36040)

"If I understand the issue correctly, I don't believe ther is a problem. The Woodcrest systems are based on FB-Dimm and that where the advantage is. FB-Dimm is serial ram. And the 5000x chipset does support dual and qual channel modes ( not 6 channel supported by FB-Dimm ) and this means with 8 Dimm's that it would use 4 channels with 2 FB-Dimms on each channel.

Supermicro has a server board that has 16 FB-Dimm's on it - which means that it has 4 FB-Dimms on 4 seperate channels. Also quad channel is twice as fast as dual chanel. IE with Dual channel 533Mhz ram is 8,528 MB/s but with quad channel it is 17,056 MB/s"
http://forums.2cpu.com/showthread.php?t=77199

Some reading about FB-DIMM:
http://www.valueram.com/fb-dimm/default.asp
http://www.supertalent.com/tools/FBoverview.php

jeffy
28th March 2007, 16:28
Take a look here:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2000110574%201371026711&name=Socket%20771
http://www.crazypc.com/products/50091.html