Mix 2 brands RAM - lower core DRAM frequency?

[hicountryrider]

On my Dell 530 XP SP3 32bit system I had switched out the original Dell supplied Nanya DDR2 800 2x1GB sticks with 2 x 1GB of Corsair XMP DDR2 800 sticks I had inherited. The Corsair seemed to have tighter timings at 5-5-5-18-22 than the Nanya at 6-6-6-18-24 (not very memory timings knowledgeable so hope I posted this correctly).

System has been OK with the Corsair for the last couple of years. But, as usual, got a little bored and said "Hey, why don't I use the Nanya sticks and double my SDRAM total?" I know that with 32bit XP I wasn't going to see the full 4 GB and indeed RAM total shows as 3.25GB but the DRAM frequency has dropped from 400 Mhz to 332.5 Mhz.

Memory is installed as follows:
Corsair - Slots 1 and 3
Nanya - Slots 2 and 4

Slots 3 and 4 have the same readings as 1 and 2 so didn't see the need to show screenshots.

The question I have (FINALLY!) is am I better off running just 2 GB of RAM (the Corsair) at 400 Mhz or having 3.25 Mhz of RAM (over a 50% increase) but running at the lower core frequency of 332.25 Mhz?

AIA any responses.

 

[VirtualLarry]

more ram is generally better than less but faster ram

 

[hhhd1]

you can set the timing manually to nanya jedec #3 and have them run at 400mhz timing 6

 

[hicountryrider]

you can set the timing manually to nanya jedec #3 and have them run at 400mhz timing 6

That sounds like a way to go. Running at the 6 timing @ 400 Mhz would seem to be better than running at 5 timing @ 332.5 Mhz. Am I wrong?

Now, any suggestions on how to accomplish this? Remember, this is a Dell system. The AMI BIOS (Dell version) has absolutely no options for memory settings. Heck, I can't even access the hard drive SATA mode settings. It only lets you set the time and the boot device priority.

Any other way to do this?

Edit: I listed the wrong BIOS above. That was for my Sony Vaio laptop. The Dell is running an Award BIOS and it does have quite a bit more in the way of options but still does not have any memory timing options at all. In BIOS System Info I did confirm that all 4 GB of RAM were visible and were running at 667 Mhz.