Specific RAM help re: bottlenecking plz.

[holmes108]

Hi there. I currently have 1GB of RAM (2X512) and am looking to upgrade to 2GB. My computer only has 2 banks, so unfortunately I have to replace it all.

Now I have a pretty good idea of what my motherboard will take. I currently have PC3200... and I know I can put in PC2100, PC2700 or PC3200.

I've recently been reading up online trying to get a better handle on what these actually mean, aside from "bigger is better".

I'm running an Althon XP 2800+, MB: ECS-KM400a.

I've used CPU-Z to detect my computers performance, and it says my BUS speed is 135Mhz, rated at 270Mhz..

Now, through my limited experince and what I've read, it seems that although my current RAM is supposedly 400Mhz (PC3200) that anything beyong 266Mhz (PC2100, I believe??) isn't going to help. Is this correct? I was under the impression that you're losing out on processing if your ram is slower than your bus, but I can't find anything suggesting I would have a benefit with RAM faster than my bus.

I'm just wondering because if I won't get the benefits of PC3200 RAM, than I can probably save a couple bucks going to PC2100...

One last question... I've heard that RAM is backwards compatible... ie: I could run PC4200 ram, although obviously it wouldn't run that fast. Is there a limit to this? Could I actually run PC6400 RAM, if it's 184 PIN? Just wondering in case I came across a good deal on faster RAM....

Sorry for the long post, just wanted to give as much info as possible. Any help would be greatly appreciated.

Thanks in advance,
Holmes.

[kenjutsuka]

Your memory settings (speedwise anyway) are set by FSB:DRAM setting, if you noticed this in CPU-z. On some motherboards (that have the feature) you can change this ratio to increase your memory speed. With RAM, PC3200 is rated for 400MHz operation. Not that it's necessarily running at that speed, but 1:1 on FSB:DRAM, it runs faster than PC2700, etc. at the same ratio. Another thing to look at is the timings on the memory. 2-3-3-5 isn't bad on DDR,espicially with a cas latency of 2. Your motherboard may support changing the timings on your memory, I need to know a couple of more things about your mother board before making a suggestion, such as what option features are included in your BIOS as settings for the memory? Does it give you any control over the settings?

[holmes108]

Thanks for the reply.

My Bios settings are as follows... all options are customizable. Also, it's my understanding that the lower the number, the better. So in the bracket, I'll put the lowest option I have available (assuming I'm not already at the lowest). I don't know if there are risks to lowering the numbers, such as the CAS Latency?

Bank Interleave : Diabled (I can choose 2 bank/4 bank)
CAS: 2.5 (2, 1.5)
TRP: 2T
TRAS: 7T (6)
TRCD: 2T
DRAM Burst Length: 4
DRAM Command Rate 2T (1T)

[kenjutsuka]

The risk would be that your computer won't boot. The lower the memory timings(higher settings in other words), the more voltage the sticks of ram eat. If you have manual overvoltage on your mobo, then you'll have to change the voltage yourself, careful though, this kind of stuff can cause damage to your memory, and manufacturer warranties don't cover overclocking. At those settings, I don't see much point in changing anything. Not a terrible loss or gain in performance.