DDR2 1066 Question

lukeyd13 · 19 Aug 2009 at 18:06

hi question regarding DDR2 1066MHz ram, say i was using this mobo Asus M4A785D-M Pro AMD 785G

http://www.overclockers.co.uk/showproduct.php?prodid=MB-357-AS

and something like a phenom 550 BE or phenon II X3 720

if i were to put the sticks in would it run at 1066Mhz by default, the reason i ask is because i have heard many storys of people saying PC8500 ram is just PC6400 ram which is overclocked. I have also heard many people saying they brought PC8500 and were unable to get it to 1066Mhz and had to leave it at 800Mhz.

I imagine this is a very noobish question so sorry in advance

RJC · 19 Aug 2009 at 18:09

PC8500 is overclocked pc6400 I beleive and in most cases you will need to manualy setup the speed in the BIOS anlong with timmings and voltage.

Were others have failed to run at stated speed may be the case the board does not support pc8500 ram or they a have faulty stick or user error.

lukeyd13 · 19 Aug 2009 at 18:29

RJC said:
PC8500 is overclocked pc6400 I beleive and in most cases you will need to manualy setup the speed in the BIOS anlong with timmings and voltage.

Thanks for the reply, thats the impression i got, so it doesnt come preoverlocked? If thats the case i dont see why you'd pay the extra for PC8500

!TIMMY! · 19 Aug 2009 at 18:36

You pay the extra because with the right mobo it is guaranteed to run @ 1066 whereas a 6400 set might not reach 1066.

GeezerButler · 19 Aug 2009 at 18:57

I had some Crucial Ballistix '1066' RAM previously and could never get it to run at a stable 1066MHz. I replaced it with some real Crucial PC2-8500 and ran out of the box at 1066MHz. 'Real' PC2-8500 runs at 1.8V rather than (for the Ballistix) 2.0V but has higer latency.

gurusan · 19 Aug 2009 at 19:00

That's not true. There are no DDR2 SPD settings that are programmed for 1066mhz.

You will need to manually set the rated frequency and timings for anything above 800mhz.

lukeyd13 · 19 Aug 2009 at 19:13

i think ill just go for the PC6400 to save myself the hassle of messing around with timings and all that. Thanks for the quick response

GeezerButler · 20 Aug 2009 at 18:37

Crucial 16HTF25664AY-1GAE1

SPD Timing Table Entry #3:

Frequency:555Mhz CAS Latency:7 RAS-CAS:8 RAS Precharge:8 tRAS:25 tRC:33 Volts:1.8v

Big.Wayne · 21 Aug 2009 at 16:30

GeezerButler said:
some real Crucial PC2-8500 and ran out of the box at 1066MHz

gurusan said:
There are no DDR2 SPD settings that are programmed for 1066mhz

While in essence you are correct it seems the some memory can plug'n'play straight in at 533MHz

I'm using some Corsair Dominators DDR2-1066 that runs out the box at 533MHz, was quite suprised because as you say most of the kits require a quick visit to the BIOS to adjust the frequency . . . I'm not sure if this is effected by being on a motherboards approved QVL list? . . .

area51 · 25 Aug 2009 at 00:20

Hi ive been having that problem mentioned.Ive 4x1gig of cruicial ballistix 8500 @2.0v.
Using an evga nforce 680i m'board that wouldn't run stable as kept going into safe mode.
even tried 800mhz.Which crucial said it wouldn't run @1066 on that board?
All working now. set dram [email protected]hbridge @1.4v. fsb 1.4v
It does seem that you do need to up the volts across ram if using 4 slots and northbridge to get stable.plus read review on mobo which said that got a lot better readings etc if fsb had voltage increased from standard/auto.
forgot to add @ 5.5.5.18? anyway standard what comes on ram. might go and have a play to see if can improve it soon?

XiS111 · 25 Aug 2009 at 00:56

im having the same problem with my OCZ Gold 4gb 8500 ram. My motherboard supports it but i cant get it to run higher than 6400 speeds, if i force it on, reboot it doesnt even pass the power of self test.