Gigabyte GA-990FXA-UD7 Planning

[rayj]

I am planning a box based upon the Gigabyte GA-990FXA-UD7 and an AMB 8150. The MB spec says it is good for 2000MT/s memory. The CPU says Up to DDR3 1866, supported with 1 DPC (DIMM per Channel) in single memory slot motherboard designs.

I would like to get good performance and not pay for more than can be used.
1) What is menant by "1866, supported with 1 DPC (DIMM per Channel) in single memory slot motherboard" in relationship to the UD7 motherboard? What type of memory options are of value here?
2) I would like to start with 16 GB. and latter, possibly expand to 32. What are some of my options for efficiently doing this?
3) What are the MB settings and what are the options?

Thanks,
rayj

[Tradesman]

1) The FX CPUs can run 1866 sticks, but (under warranty) you are limited to 1 stick per channel or 2 total sticks/DIMMS, in other words, you might be able to get a 4x4GB set of 16GB running, but it will void the warranty.
2) For 16GB you should be able to run 4x4GB of 1866 (but keep in mind it voids the CPU warranty) and it will probably take some tweaking as far as voltages. A better bet might be to go 4x4GB of 1600 with those I'd suggest the Snipers F3-12800CL9Q-16GBSR, or the Ripjaws F3-12800CL9Q-16GBRL. If you want to try 1866 and have a good safety net look at the 4x4GB Ripjaws X F3-14900CL9Q-16GBXL, if problems exist at 1866 can drop to 1600 and tighten timings down to about 8-9-8-28 or so which will produce near 1866 performance and would be better than the native 1600 sets (which are CL9)

As far as mobo settings, you'll want the latest BIOS, from there you should simply need to select the DRAM speed/freq you want and then ensure the base timings match those on the package, Command timings sets to 2N or 2T and voltage is correct per spec on package

And lastly - if you do have any problem, give a shout, if not, give a shout anyway and let us know what you think

[rayj]

Re: Gigabyte GA-990FXA-UD7 Planning

Tradesman,

Thank you very much for the rapid, detailed response.

I did not see a warranty for the CPU. I am suprised that the CPU has stick count limits since it interfaces with the northbridge and not the sticks. I guess I should find the warranty to get a better feel for the memory configuration conditions. Is this limit typical for all FX990s?

I am sorry, I don't understand what you mean by the term 'good safety net'. I do not want to void a warranty.

As a secondary, what might be an alternate to the 8150 for 16 GB memory and speed?

I'll check out the info/specs on the 3 models you mentioned.

rayj

[Wallace]

Hi rayj,

I have the setup you are thinking about. The FX-8150 will run at 1333 without having to alter the BIOS settings for the SNIPER 4X4 set. You can probably get it to run at 1866 but you may need to play around with your bus settings and possibly increase your voltage a little on the RAM. As an alternative, you can tighten the RAM settings at 1333 and approach 1866 performance.

Wally

PS The memory controller is on the CPU die and is not in the NB chip. This is why you can void your CPU warranty by OCing your memory controller. It's generally refered to as the CPU NB to differentiate it fron traditional NBs.

[Tradesman]

By safety net, I simply meant you can drop them to 1600 and run tighter timings for near 1866 performance, as an alternative, I'd definitely suggest going with a 2500K and a P67/Z68 mobo. The 2500K cost less than a FX-8150 and outperforms it by far. It also easily handles 16+ GB of DRAM up to 2133+

[rayj]

Tradesman,

Thank you. I understand much better now. I can slow down from 1833 to 1600 but tweak the timing to maximize perfromance at 1600.

You mentioned the 2600K could run 16G at 2133, that is impressive. Can it run 32G?

I am sorry that I did not explain more of my appication(s). My plan is for a workstation running XCP with the Xen hypervisor. Thus it will have multiple VMs. I aplan on performing a PCI pass through of a graphics card to one of the VMs. I would like to be able to remote into the host from a remote location. The 2600K does not have the full complement of VT features.

rayj

[rayj]

Wally,

Thank you, that was a clear presentation and including the 'whys'. I appreciate your recommendation.

rayj

[Tradesman]

I've read a couple places where it's been done, and one of the builders I network with has built one, says all is fine, I myself have yet to find a customer that want's to pony up almost a grand for a 4x8GB set of 2133. Did the 2600K and 32GB of 1866 which was OK, took a little voltage tweaking