View Full Version : Can PC3200 be used in conjunction with PC2100?

02-03-05, 03:56 PM
I just have a few quick questions about RAM. For my upcoming computer upgrade I'm picking up a gig of PC3200 from my friend, but I'm probably not building my new computer until the end of the month. So in the meantime, would it be alright for me to add that gig of RAM to my current 768 megs of PC2100? My current motherboard only runs at 266 FSB, and obviously if I add the PC3200 it would only run at PC2100 speeds, but I'd just like to know if there would be any problems using RAM rated at different speeds/latencies togeather.

Which brings me to my second question. Is there any way to check the CAS latency on the RAM without finding out the manufacturer/type? Supposedly the RAM my friend is selling is really, really generic, and it doesn't even have the latency or manufacturer information on the chips themselves. Presumably it's 3.5 or 3.0, but I'd like to be sure. And how much would 2, 512 meg PC3200 chips usually go for? Newegg had some for $130-$140, but otherwise I'm not sure how much RAM is really worth nowadays.

02-03-05, 04:10 PM
Ok, first answer, there isnt any problems with running the 2 different speeds, but some motherboards are picky, and might not like 2 different types. Best shot is to give it a try, but like you said, the PC3200 will run at PC2100 speeds. Your better off taking out the PC2100 ram, and running the PC3200 alone.

Second answer, odds are the CAS on the generic ram is 3. I would doubt its 2.5 or 2. There is a way to check it, put it in the system, and run CPUZ http://www.cpuid.com , it will tell you the CAS settings.
2 x 512mb ram vary's in price alot. for example, my ram Gskill PC3200 (2-2-2-5) runs $289. But its also high performance ram, for lower performance stuff, like generic or something can get pretty cheap.

02-03-05, 04:38 PM
Cool, thanks for the quick reply. I guess my best bet would be to try running it with only my old 512 stick and the two new 512 sticks and seeing if it has any problems, since the extra 256 stick wouldn't help much anyway. Thanks for the link to that program, I'll have to check that out once I have access to the RAM. What do the 3 or 4 numbers after the speed indicate? The first one I assume is the CAS latency, but the rest I haven't been able to figure out. Also I noticed you can actually set the latency values through the BIOS, will changing that setting actually make the ram run faster than it's rated (at the risk of instability, of course)? Or is the latency locked on the RAM itself?

Thanks again for your help, I appreciate it.

02-04-05, 01:20 PM
I would just use the 1G of 3200 and not worry about the other 2100ram since you want see no inprovement in games with running 1.75g of ram unless you do something like video editing.