PC1600 RAM unstable at rated speed?

[yiplong]

No matter what I do I could not get my PC1600 DDR3 ram to run at its rated speed. My CPU is a P2 X3 720. I am suspecting that the CPU's memory controller may not support 1600mhz memory. Can anyone confirm this?
I now run the memory at 1333mhz but with a tighter timing (8-8-8-21 instead of 9-9-9-24).

[scaryjim]

You're quite right, officially Phenom IIs only support DDR3 up to 1333. SOme motherboards provide overclocking profiles to run the memory at higher speeds, but it's not officially supported. They also only support up to 2 sticks of memory @ 1333MHz - use 4 and it'll automatically downclock to 1066MHz!

[jim]

I wouldn't worry, it's not going to make a massive difference.

[golwg]

Is that the same with Intel?

[jim]

Not that I'm aware of, you can go up to stupid speeds with Intel.

But according to Nightkhaos, it's a waste of time with i7 (I don't know much about it personally) because it just creates a lot more heat and power consumption for very little gain.

[CAT-THE-FIFTH]

I would read this article:

http://www.tomshardware.com/reviews/...ddr3,2319.html

DDR3 at 1333MHZ using lower latencies is better than DDR3 at 1600MHZ using higher latencies for the Phenom II memory controller as it seems to be more latency dependent.

Also the C3 stepping Phenom II processors support 4 banks of RAM at 1333MHZ.

[LuckyNV]

Is that the same with Intel?

Yes, official support for LGA1366 is 1066MHz and LGA1156 is 1333MHz, but either can exceed without any large problem.

Same with LGA775, official was DDR2-800 or DDR3-1066 (on P45 chipset), but motherboards allowed support for higher and without large issue.

[yiplong]

You're quite right, officially Phenom IIs only support DDR3 up to 1333. SOme motherboards provide overclocking profiles to run the memory at higher speeds, but it's not officially supported. They also only support up to 2 sticks of memory @ 1333MHz - use 4 and it'll automatically downclock to 1066MHz!

My motherboard does support PC1600 OC, but I still cannot get it to run stable. I guess I will stay with 1333 using the tighter timing.