I just bought 256 meg of ram for my laptop and noticed the original 256 meg is 133 mhz ddr and the new 256 ram is 266 mhz ddr, should I run them together to total 512 meg ram or will the old 133 mhz ddr slow the new 266 mhz ram down?

You *can* run the same *type* of ram as you said you have DDR. The slower 133 mhz WILL be what both will run at but you will still be gaining running that much more ram. Best Wishes,Randy J. [email protected]" A little learning is a dangerous thing"AMD XP2100 |MUNCHKIN512 DDR RAM |ECS[/b ]K7S5A MB |[b]GF364 MEG |WIN XP PRO

It sounds like you might be confusing SDR with DDR... While PC2100 DDR runs at a real 133MHz, because of its design it actually works at 266MHz (and is sold and rated as such).PC-133 is the old standard SDR SDRAM - it both runs and works at 133MHz. If this is what your laptop has in it now, you can't use DDR along with it (and probably can't use DDR at all - I've never seen a dual DDR/SDR laptop chipset that does at least, unlike the SiS desktop chips that can handle either).Verify what you have first. If the existing is PC-133, you'll need PC-133 DIMMs to upgrade. If indeed you have 266MHz DDR (running at 133 real MHz), you bought the right DIMM already.Good luck,Elrond