RAM Conflict

[tostet]

I'm trying to add Ram in the 2nd socket on a Compaq Presario 2100 (2104US)
All literature and websites say it should have PC2100 DDR266 200Pin Ram installed.
The laptop came with following in the first socket: PC2700 DDR333 256MB.
Why this is installed is confusing
I'm trying to figuire out what to buy.
Is there a conflict with installing the suggested PC2100 with the PC2700

 

[IEC]

If it is running at DDR266 (PC2100) then there should be no problem with using a PC2100 chip. However, if it is running at DDR333 then you should buy a PC2700 SODIMM in order to run at the matched speed.

 

[tostet]

So either type of RAM should run in this laptop, just don't mix them?

 

[Ruptga]

Either should work, but if you use 266 memory with 333 memory, they will drop down to the slowest speed, so your memory will run at 266 instead of 333 like it does now. Just get the 333, it's more common than 266 so it's actually probably cheaper, and you don't have any chance of losing performance with it.

 

[tostet]

I wasn't aware you could change the DDR speed from what is specified for the laptop.
I'm not a techie, or is that obvious?

 

[Ruptga]

Originally posted by: tostet
I wasn't aware you could the DDR speed by upgrading RAM

I assume you mean "could drop the DDR speed." The system will run your memory at the speed of the slowest module, so if you add a stick of 333 to a stick of 266, there will be no difference, the system wll run at 266. If you add a stick of 266 to a stick of 333, the system will run at 266, a 20% drop in memory speed.

You cannot raise the speed of slower memory by adding in faster memory, but you can slow a fast system by adding in a stick of slow memory.

Edit: in line with your edit I'm editing. You cannot run the memory faster than the system will support, but you can make it run slower if you put in slower memory. Back in the day of SDRAM you couldn't put in slower memory, it simply wouldn't run, but anymore the system will auto-detect what you have in and slow the memory down if necessary. In any case it never hurts the system one bit to put in memory that's faster than what you need.

 

[tostet]

So hypothetically if I started over with all new ram, then I could install even higher speeds as long as they matched the 200pin config? And that wouldn't conflict with the laptop specs/requirements?

 

[Ruptga]

Originally posted by: tostet
So hypothetically if I started over with all new ram, then I could install even higher speeds as long as they matched the 200pin config? And that wouldn't coflict with the laptop specs/requirements?

That's right. The worst case scenario there is that your system won't support the higher speeds and it will revert to your previous memory speeds. Higher speed memory sometimes costs more, so you could waste money, but if the higher-grade memory is the same price, take it. At worst you'll see no improvement and you'll have memory that's easier to resell/reuse later.