I'm down to the last piece of my upgrade, the RAM. I currently have DDR 400 PC 3200 2x512 at 2.5-4-4-8. I have three slots on my MB and I checked with the MB manual to make sure I could add another stick.

I want to add a 1GB stick, and it's my understanding that if I want to keep the timings of my current RAM, I need to get the same numbers or lower. If I get higher numbers, the existing sticks will sync up with the longer frequencies of the additional stick.

It's difficult to find DDR400 1GB DIMMs at 2.5 CAS. If you've been following my posts, you know I have a $50 GC for Tiger Direct that I still need to use. (Got my PSU through Buy.com) They don't have anything under 3.0 CAS. (BTW, Tiger Direct stinks compared to Newegg).

Newegg has this nice one.

My question is, how much performance am I going to loose out of those two 512 sticks if I go with a 3.0 CAS third stick that will slow down the two original sticks?
Is it possible to over clock just the one DIMM to get it down to 2.5 from 3.0?

Thanks,

Wurum.

In ordered to keep the mobo running in a dual channel mode all your sticks
of ram need to match up.

Quote: Originally Posted by Slaymate In ordered to keep the mobo running in a dual channel mode all your sticks of ram need to match up.

My mobo only has 1 channel

I've read some more, and I think I'm confusing overclocking and setting the timing. My BIOS allows me to set the timings, and I've read a couple of comments that they have no trouble setting a 3 to a 2.5, so I think I'll try that. It just sucks that DDR is more expensive than DDR2 right now.

Quote: Originally Posted by Wurum It just sucks that DDR is more expensive than DDR2 right now.

I feel your pain man! I am running all 3 of my machines with DDR. Luckily between the 3 I have 6GB.

I eneded up buying that 1GB of G.Skill at 2.5-3-3-6 from Newegg and popped it in last night. Sandra is saying that my two DIMMs are at their respective timings of 2.5-4-4-8, and that this one is at 2.5-3-3-6.

I have to look at it again, it was late last night and I don't remember where I saw it, but I saw a timing of 2.5-4-4-7, as if it was averaging the timings across all the DIMMs. I do have 2 GB of ram now, but some of it got slowed down. I saw an FSB of 167MHz or something and the 1GB is at 200MHz as it supposed to be. The 2x512 sticks are reporting DDR(367) or something.

I was running Memtest86 from my BIOS and there were some errors on test 5. I got tired of waiting for the test to finish, so I rebooted. I'll do some more testing tonight. I'm wondering if the memtest errors were due to the old sticks. I didn't test them before adding the new one. I'll have to take the new one out, test the old ones and see what happens.

OK, I got all 3 sticks to run at 400 MHz Memory Bus Speed. It's actually 2x201 = 402. I don't know why though, I went into the BIOS and changed the DRAM Frequency Set from Auto to 200 MHz. It's supposed limit the frequency to 200.

Anyway, Sandra was showing the Logical/Chipset 2 Memory Banks had the 2.5-4-4-7 timings. And that was giving me a Memory Bus Speed of 2x164 = 328.

After setting the DRAM Frequency Set in the BIOS to 200, the timings on the Logical/Chipset went to 2.5-4-4-8 and the Memory Bus Speed to 2x200 = 400.

So, while I'm not taking advantage of the faster timings on the Trd, Tras and Trp on the new G.Skill stick, they are all running at the 2.5 CL, and I'm getting 400 MHz.