F2-8500CL5D-4GBPQ with GA-MA770-US3

[joeyan]

Hi Everyone,
Actually I'v already read all related topics in this forum, but I'm still very confusing.
I googled for F2-8500CL5D-4GBPQ vs. F2-8500CL5D-4GBPK, and found the difference is that F2-8500CL5D-4GBPQ specifies 5-6-6-18 as the CL while F2-8500CL5D-4GBPK specifies 5-5-5-15. And, on the box of my F2-8500CL5D-4GBPQ, there's a label says 5-6-6-18.
What confused me is that this forum is always telling user to configure every 1066 RAM to 5-5-5-15 regardless to the model No., so why the 5-6-6-18 comes onto the box and the official SPEC?

My motherboard is Giga GA-MA770-US3
The CPU is AMD Phenom X3 8450
The RAM is F2-8500CL5D-4GBPQ (2G*2, in correct slots)

I've tried 1066 @ 5-5-5-15, but the computer stops responding right after it's started.

So, I'm here looking for a detailed instruction to help me get my new RAMs working at 1066mHz.

I appreciate your support~ thanks

[Tradesman]

Used to be RAm fell into a specific mathematical formula on the base timing the first threee were added together to get the fourth i.e. 5-5-5-15, 6-6-6-18. etc. but more and more DRAM Manufacturers are trying to fine tune the RAM a bit to draw additional customers. In your case to get the CAS Latency at 5 they have to relax the other settings a bit to 6-6-18

Go ahead and manually set it at 5-6-6-18 and you should be fine, or if you want to play with it, you could drop the speed to about 933-966 and drop it to CL4 (maybe 4-5-5-15) and you might even actually outperform the same sticks when they are running at 1066 w/ 5-6-6-18.

[joeyan]

Thanks Tradesman, your reply is excellent.
I'll have a try

[Tradesman]

Hope it helps out, been out of touch here for a week or so.....but trying to catch back up