Memory bus overclocking of E5 CPUs possible?

[Andreas]

Quick question to the community

In the review of the SuperMicro HyperSpeed Server
Dual Xeon E5 Memory Bandwidth Comparison - DDR3 1066MHz to Hyper-SpeedServeTheHome ? Server and Workstation Reviews

Memory speeds of 1066, 1333, 1600 and 1866 MHz had been investigated. Intel lists 1066,1333 and 1600 MHz as valid memory speeds, but not 1866 MHz in the current generation of Xeons (This will change with the Ivy Bridge Xeons).

While it is possible to set BIOS values to 1866 MHz, the memory controller of the E5-2600 Sandy Bridge CPUs is on-die and is locked down to a max speed of 1600 MHz.

So the question is:
What need to be done to unlock the on-die memory controller of E5-2600 CPUs to run beyond its designed speed? The memory speed setting in the BIOS of the motherboard does not change the speed of the on-die memory controller above 1600 MHz.

Background:
None of the hardcore overclockers had been successful in raising the memory speed beyond 1600 MHz on the Xeon CPUs. Does Supermicro uses special "unlocked" E5-CPU's nobody else is getting? I am not confusing this mem-overclocking with the BCLK setting (which is the only known way to speed up E5 Xeons by a couple of %)

Thanks for any technical insight,
Andy

 

[Biren78]

Quick question to the community

In the review of the SuperMicro HyperSpeed Server
Dual Xeon E5 Memory Bandwidth Comparison - DDR3 1066MHz to Hyper-SpeedServeTheHome ? Server and Workstation Reviews

Memory speeds of 1066, 1333, 1600 and 1866 MHz had been investigated. Intel lists 1066,1333 and 1600 MHz as valid memory speeds, but not 1866 MHz in the current generation of Xeons (This will change with the Ivy Bridge Xeons).

While it is possible to set BIOS values to 1866 MHz, the memory controller of the E5-2600 Sandy Bridge CPUs is on-die and is locked down to a max speed of 1600 MHz.

So the question is:
What need to be done to unlock the on-die memory controller of E5-2600 CPUs to run beyond its designed speed? The memory speed setting in the BIOS of the motherboard does not change the speed of the on-die memory controller above 1600 MHz.

Background:
None of the hardcore overclockers had been successful in raising the memory speed beyond 1600 MHz on the Xeon CPUs. Does Supermicro uses special "unlocked" E5-CPU's nobody else is getting? I am not confusing this mem-overclocking with the BCLK setting (which is the only known way to speed up E5 Xeons by a couple of %)

Thanks for any technical insight,
Andy

Is this new? I thought Dell and Supermicro both allow for 1866 speeds on their HFT systems? Looks like SMC is actually getting them from the benchmarks.

 

[Andreas]

Is this new? I thought Dell and Supermicro both allow for 1866 speeds on their HFT systems? Looks like SMC is actually getting them from the benchmarks.

New would be that somebody found a way to circumvent the 1600 MHz lock of the E5-2600 series CPUs. Either with or without Intel's blessing. This is my question.

 

[Biren78]

If Dell and Supermicro are doing this then Intel knows about it. Dunno if HP does.

 

[Andreas]

Thank you Biren.

But the question how to unlock the E5 Xeon CPUs to run above 1600 MHz isn't clear to me.
Setting 1866 MHz on the motherboard reports 1866 MHz from the BIOS, but if you check with CPU-Id and similar HW Tools at runtime they continue to show 1600 MHz (or 1680 MHz if BCLK is set to 105 MHz).

Strange,
Andy