DDR2 6400 800mhz a waste for Conroe

Flanno · 8 Jun 2006 at 19:05

Just reading a little bit about Conroe and like the 3.7EE 965 it has a 1066mhz fsb which comes in at 8.5GB/s. DDR2 6400 memory that runs at 800mhz has a peak of 12.8GB/s. The Intel Nforce 590 is going to be limited to DDR2 5300 667mhz though, which is 10.6GB/s but still more then enough for Conroe. While the Intel P965 will support DDR2 6400 800mhz, but it seems unlikely you will be able to take advantage of this speed. So it would seem anything over DDR2 5300 is a waste, other then using DDR2 6400 at 667mhz speeds instead of 800 mhz speeds and attempting lower latencies, or possibly overlocking the hell out of your Conroe to get close to the 12.8GB/s limit of DDR2 6400. The only other use I can think of for DDR2 6400 is in situations where hard drives, pci cards, and other i/o devices uses bus mastering to read from memory directly without going through the front side bus.

Some interesting info. here on Nforce 590 and Intel P965
Notice how the P965 will not support sli or xfire.

http://www.behardware.com/html/news/cat3/page1.html

Flanno · 9 Jun 2006 at 15:03

Yeah...I bought one...doh!

Flanno · 10 Jun 2006 at 15:28

I have an nforce4 mobo and it wont support higher then 667mhz. Wont even boot !! So at 667mhz speeds is benches around 5k in Sandra. Same as the memory it replaced.

I did bench it in my friends 975x mobo with Sandra. And ran it at 800mhz with low latency (3,4,3,9) and at 1066mhz at 5,5,5,15. Fast improvement in scores. But it means nothing though, as that is purely a theoretical memory benchmark as the cpu's max. bandwidth is far lower then what DDR2 800mhz is capable of. That's what you get for going through the front side bus and not using an integrated memory controller like AMD.

Still I have a 975x mobo coming next week as am having major warm boot issues with this nforce4, and it undevolts like crazy. I will be able to run at 800mhz native, for all the good it will do me.

Flanno · 10 Jun 2006 at 20:28

Yeah..RamGuy on the corsair compatability forums advised the 6400c3 over the 8500c5 as it uses the same IC's and should do 1066 no problem, but the 8500 would probably not do low latencies of 3,4,3,9 at 800mhz.