Tyan s7012 not running ram at full speed

[gr8ape]

Hello, all! This forum has been immensely helpful, so I was hoping y'all could help me solve another conundrum:

I'm running HMT31GR7BFR4A-H9 in a Tyan S7012GM4NR. I have 18 of them in there. For some reason, they run at 800MHz instead of 1333MHz. If I manually set the ram to 1333MHz, not all of it is detected. I'm using dual L5630.

I just realized as I was typing this, I have the same ram in a Supermicro X8DTE-F fully populated (12 slots I think), and that only runs at 1066MHz instead of expected 1333MHz. In this one I'm running dual L5640.

Thank you for any suggestions on insight you may be able to provide.

 

[j_h_o]

L5630 only supports 800 or 1066: Intel® Xeon® Processor L5630 (12M Cache, 2.13 GHz, 5.86 GT/s Intel® QPI) Specifications

 

[britinpdx]

I think that is expected and normal operation !

Populate banks 1 and 2 only and the memory will run at 1333MHz.
Add memory to bank 3 and everything drops to 800MHz.

Fujitsu have some great white papers that discuss their server architecture and performance. Here's one that talks about Memory Performance on the Westmere Architecture (56xx family). The image on page 5 calls out the different Fujitsu configurations, but the block diagram I believe is valid for the S7012 motherboard.

 

[britinpdx]

I stand corrected, I didn't pay enough attention to the CPU call out. @j_h_o is correct, the max frequency of the L5630 is 1066MHz, so with banks 1 and 2 populated the max freq will be 1066MHz, not 1333MHz.
Max memory performance for the 56xx family is called out on page 12 of the Fujitsu white paper I linked.

 

[gr8ape]

So if I'm reading this right, as page 14 outlines, 3-way interleaving, despite being 800MHz is still faster than the other modes? Or am I misreading that.