DDR3-2000 CAS8 Clock issue

[N3M]

I have been reading along on this fourm for quite a while to learn about overclocking and such while i had my old Q6600. About 4 months ago i was given an offer to sell that machine and i thought it would be a great opportunity to build a new i7. I have never had any problems with it and now i decided i want to actually get up and max my machine out. When i built the machine i went with 6 gigs of kingston 1600 memory and it was default clocked at 1333 and i didnt really care at the time because it wasnt much of a jump, but I reciently purchased some more expensive DDR3 2000 memory from kingston (KHX2000C8D3T1K3/6GX).

System Specs:
Processor: Intel Core i7 975 Extreme
MotherBoard: GA-EX58-UD4P
Current Memory: 12gigs DDR3-2000

This memory states its XMP compatable but on profile one it freezes at windows loading screen, and on profile two it wont post. This was true as well for the older 1600 memory i had before.

Right now the memory is running at 1333mhz with voltage at 1.5v. I hear this is the standard JEDEC speed or something. How can i get this setup to run stable at 2000mhz. I already spoke with gigabyte about this issue and they said the mother board is fine and it might be my processor, and i already spoke with kingston and they said their product is working fine and that this processor is only rated for memory up to 1066mhz (I dont believe that as its already running at 1333 which is faster than 1066).

Any help or input would be greatly appriciated.

 

[Ross]

Forget the profiles and set it up manually. Profile2 raises BCLK to 143, which seems to be a weird area. Also, QPI/Vtt is overly high on Profile2.

Try this:
BCLK = 167 (adjust CPU multi down if needed)
mem ratio = 12.0 (2004Mhz)
mem voltage = 1.66V in BIOS
manual mem timings = 8-8-8-20 or 8-8-8-24 (leave advanced section timings alone for now).

Leave everything else alone and see if that boots. If that seems OK, try readjusting to 7-8-7-20 or 7-8-7-24 and see if that works. Depending which Elpida ICs are on the mem, it may or may not do CAS 7 @ 2000MHz with ~1.65V. You also have a lot of mem which doesn't help for tightening things up, so start with 8-8-8 and we'll see what happens.

 

[N3M]

I tried doing just as you recommended and it wont post. The multiplier ended up being at 20x to get those settings and the QPI Link Speed moved to 6.01GHz as a result. Do you have any other suggestions and is there any easy way to copy my bios screen and post them here? Thanks for your help it is greatly appriciated.

 

[Ross]

X58 can be a little picky about running mem fast, so this may take some tries and be prepared for the realization that you may just end up running them at lower than default speed with tighter timings. I have the same sticks and have to run them below 2000MHz (1700-1900MHz) because the uncore gets too high because of the mem ratio+BCLK I normally use. That's a CPU limitation, but you shouldn't near it yet.

You have 6 sticks? Try it with 3 first and see if that works with the settings above. It just may be a lot tougher with all the slots full (and may take a bit more Vddr and Vtt). I've only run 3x2GB, which is what I am going by.

If 3 sticks still doesn't work with the settings above, we'll work on trying to keep the speed first and back into the timings. Put all the sticks in and try 9-9-9-24 timings and 166 BCLK instead and we'll go from there.

The QPI should be just fine at that speed, but maybe try setting it to 32x to make it a little easier on the CPU for now.

There's no easy way to do a screen capture in BIOS that I know of. You can take a couple of pics and/or just find a "BIOS template" and fill it in with your settings manually and past it in a post. We don't really need most of it, just multis (mem, uncore, CPU), primary mem timings and voltages are the important things for now.

 

[N3M]

I appriciate all your guys inputs. I am not having much luck with with this but i will report back later tonight after i do some more tests. Im open to more suggestions, thanks guys!

 

[N3M]

Does it matter what you do to achieve your memory speed? Is it better to shoot for a low or high multiplyer for the cpu and memory or a low or high BCLK?

 

[Ross]

Higher BCLK is better for overall perf, but for mem, it generally doesn't matter which ratio. You may "have" to run a certain CPU multi or mem ratio depending where you land for BCLK and what your CPU/sticks will run at. You'll just need to play around to find BCLK that maximizes both with voltages/temps you are comfortable running at. CPU multi won't make any diff for performance, but 200x21 will perform better than 168x25 because of the BCLK even though the CPU will be running the same 4.2GHz either way.

Keep in mind, the higher the BCLK, the more voltage you'll need for stability. If you can get 200 BCLK, great. That's a nice round number and reasonably high. The 8x mem will give you 1600 even or 10x for 2000MHz if you can stabilize it that high. Other than that, something in the 160-185BCLK range will be easier and still better than 133.

After you get BCLK/CPU/mem speeds nailed down, you can take a look at raising uncore.