Memory upgrade

vasek · 12 Sep 2011 at 18:37

Hi!

I have 2x1GB sticks, OCZ PC2-6400 4-4-4-15.

I want to keep these and upgrade to have more memory, for examply buy 2x2GB and stick them in the 2 free slots. Is that possible? And what memory should I buy?

Cheers

Plec · 12 Sep 2011 at 19:58

It's possible but you may have to drop your timings to 5 5 5 15 looking at OcUK's stock of DDR2 6400.

What is the exact model of your memory and what is the brand/model of your MB?

vasek · 12 Sep 2011 at 20:19

Is that done through BIOS?
http://www.ocztechnology.com/ocz-ddr2-pc2-6400-platinum-revision-2-dual-channel-eol.html
And I think its a Asus P5E mobo!

Plec · 12 Sep 2011 at 20:23

You can use CPUz to get the name and model of both your memory and MB.

Plec · 12 Sep 2011 at 20:27

Using the info you gave above and because of the voltage requirements of the OCZ the Kingston HyperX 4GB (2x2GB) DDR2 PC2-6400C5 would be the best match.

EDIT: Just double checking voltages as they differe on the Kingston site and the first page of OcUK.

Plec · 12 Sep 2011 at 20:36

OK, OcUK's stock of DDR2 memory is all rated at >1.85V and the OCZ memory that you linked to requires between 1.9V and 2.1V.

However, the new sticks would require slacker timings of 5 5 5 15 and as a result your OCZ may very well run at these timing at the lower voltage of ~1.8V.

I recommend that you experiment with these timings and volatge with your present memory and stress test them with a combination of prime 95 (blend) and memtest. If they pass i would recommend getting the Kingston set as it has a slightly higher voltage of 1.85V.

vasek · 12 Sep 2011 at 21:30

CPU-z says the timings are 5-5-5-15 on the memory, but the sticker on the memory says otherwise! How can that be?

Plec · 12 Sep 2011 at 21:37

It's probably not been set up properly in the BIOS - perhaps setup on auto?

vasek · 12 Sep 2011 at 22:31

Most likely! So if I buy the memory you mentioned, it should automatically be configured with the same timings as the old memory and should theoretically work?

Plec · 12 Sep 2011 at 22:52

vasek said:
Most likely! So if I buy the memory you mentioned, it should automatically be configured with the same timings as the old memory and should theoretically work?

No, you should manually set the timings and voltage when you install the new sticks to be sure it's setup correctly. Plus as you're filling all the DIMM slots you may have to up the MCH voltage (North bridge) as using 4 sticks puts extra stress on the memory controller and often needs more voltage to keep things stable.

But before you order any 6400 memory you need to test that your presnt memory will run at 1.85V at 5 5 5 15 using the test method i mentioned previously.

If it's not stable at the lower voltages you may need to buy the Kingston 8500 memory and run it at the 6400 settings as this has a voltage range similar to that of the OCZ.

vasek · 13 Sep 2011 at 15:19

Thanks, will do this tonight then!

Yellowbeard · 14 Sep 2011 at 19:50

As cheap a memory is, my suggestion is to buy either a 4GB or 8GB kit and not mix the old modules in. You'll have the best chance at a stable system by not mixing different modules.

Plec · 14 Sep 2011 at 20:32

Yellowbeard said:
As cheap a memory is, my suggestion is to buy either a 4GB or 8GB kit and not mix the old modules in. You'll have the best chance at a stable system by not mixing different modules.

He needs DDR2 memory - so 8gb (4 x 2gb) would cost him ~£120 - that's a lot to spend on a dead socket.