I recently decided to upgrade from 4gb to 8gb of ocz reaper ddr2 1066mhz memory. running 4gb was no problem, adding 4more caused system lockups,reduced graphics scores, and blue screens. Since then i have contacted AMD about the PhenomII 2.5ghz triplecore cpu i have. They told me that they successfully run 4 dimms in their test motherboards at 1066mhz without any setting changes. They told me that the memory controller in the cpu might be bad. Ocz Technologies swares that their Reaper series pc-8500 memory is of the highest quality, even though it needs to run at 2.1volts to produce 1066mhz [so it needs to be overclocked]. Gigabyte technician said that it is very difficult to run 4 dimms at 1066mhz. That most gamers only run 1066 in 2 dimm slots [hence one stick per channel].He also pointed to the memory controller on the cpu as the culprit, and said if i get "true" 1066mhz memory[the low voltage ones that run at 1.8volts], that 4 dimms "might" work at 1066mhz. So... after many days of research i am frustrated, i would like to run 4dimms because i have Windows 7 64bit operating system. I dont like the idea of overclocking the cpu or the northbridge. I just wanted some extra memory. I had the idea to look for 4gb dimms that run at 1066mhz and get a pair of those, but i have not found any on the internet so far. Does anyone have a suggestion in what direction i should go with this? or should i just give it up, and keep running 4gb? Gigabyte MA-GA790GP-UD4H board OCZ Reaper DDR2 PC-8500 1066mhz 4GB [2x2gb] 2.1volts Western Digital Caviar Green 500GB SATAII hard drive HD3300 graphics integrated on 790GX chipset Asus XonarDX sound board ThermalTake 430Watt PSU Generic Mid-Tower with 4 fans
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116.PDF im beginning to think what i hear about not being able to run 1066mhz in all 4 slots is true take a peak at pages 64-66 on the above link. Any help is appreciated.
You could use memtest on each stick of memory to test them , but i think if you have 4 sticks of 1066 they will declock to 800 mhz, the 1st to slots would run at 1066 all day but i presume in slots 3 and 4 you would get a down clock to 800 mhz on each stick, you could try and alter the voltage to your memory and of course the timings, then redo memtest on each stick to ensure stabilty , but alas i think that if you get it to run you may have to put up with 8gb of 800 mhz memory, i`m no expert but i hope i helped.
Hope I don't get crucified for suggesting this; Why not run 2 kits of G.Skill Ripjaw 4GB (2x2GB) DDR3 PC3-12800C8 1600MHz Dual Channel Kit. They are 1.65 Volt tested and run standard 8-8-8-24 values at 1600MHz so down clocking them to run at 1066MHz shouldn't be any problem. just a thought. DOH! SCRAP THAT Didn't see you had DDR2 Sorry, think you may have a hard time finding some good low voltage DDR2, most of them run 2.1-2.2V from my understanding, have you thought about loosening the timings? (standard EPP 5-5-5-18 (CAS-TRCD-TRP-TRAS)) see if you can run them at something like 5-6-6-18??
it may be a setting in the bios, check that the memory speeds are set to auto and that you hav'nt got a speed cap also a point worth noting is that some mobo's have 2 high speed slots and 2 for slower speeds and some times when you fill all 4 slots it's drops the speed to the lower rating(the same as if you fit mem with different speed ratings). That said if the boards rated for 1066 it should take it easily and as for gamers only running 4 gig thats a load of crap. I would hazzard a guess and say if all of the above checks out it may be that a component has failed or is on the way out.1 last thing 4gig sticks are plentiful but you'll need a deep wallet if you want the pleasure of using them......hope this might have shed a bit of light on your probs...keep us posted