Mixing Hyper-X speeds?

[VioLent]

okay I just got a new pair of 512mb Kingston Hyper-X pc3200 (2-3-2-5) for a real good bargain.
I was wondering if its a bad idea to mix them with my current pair of 512MB Kingston Hyper-X pc4000 (3-4-4-8)?

specs:
p4p800-e deluxe
hyper-x khx4000
2.8e p4 presscott
evga 6800gt

[Reefa_Madness]

Those two modules use different ICs, with the PC3200 using chips designed to operate at lower speeds with tighter timings (most likely Winbond CH-5) and the PC4000 designed to be operated at higher speeds, but with more relaxed timings (likely to be Hynix or perhaps even Mosel chips). The Hynix chips will most likely not run at the same low timings as the Winbond and the PC3200 will most likely not run at the 3-4-4-8 timings of the PC4000 without increased voltges, which the Hynix does not tolerate very well.

In order to run them together you will need to compromise in all areas...memory speed, timings and voltage, perhaps running them at 2.5-3-3-7 and speeds of 220-230 or something similar to that. The good thing is that at least in those memory speed ranges the voltage requirement for both ICs should be similar. Only at higher speeds will the PC3200 be likely to require increased voltages and even then, it is not common for the CH-5 based KHX to hit the 250 range of the PC4000.

As always, you will just have to test them, first to be sure that they'll even run together and then in various configurations to find the sweet spot for the two sets.

Good luck and let us know how it went.

[vulcanman09]

i use
1 256meg stick in 1 slot ( kingston )
1 512meg stick in the other slot ( infineon )
when i went into the bios
there was no memory presets
all the memory screen showed was hyphen lines all across
i am assuming that this configuration
the bios cannot lock down the memory presets

you should try this to see what happens
you never know
you might be able to overclock like hell
without a glitch

[Reefa_Madness]

The previous post does bring up a point that I forgot to mention.

If I was trying out those four sticks I would not rely on the SPD settings at all. I would go into BIOS with my current sticks and manually set the voltage to 2.6 or 2.7 and timings to 2.5-3-3-7 and CPU clock speed/FSB to 200 and attempt to boot with that as my initial setting. I believe those are settings under which both sets of modules could operate. If those settings work, then you can begin tweaking from there.

[VioLent]

okay, so I popped the sticks in and booted up to windows. Everything looks and feels fine. But I'm going to try what you said Reefa, and see if it does anything for my clocks. Thanks for the replys! Greatly appreciated.

[rseven]

When I have OC'd HyperX ram, I have found that a modes amount of extra vdimm helps. (Going from 2.7 to 2.8 volts) Good luck with it.