Thread: Memory question

I am going to upgrade to Windows 7 and need more memory for my PC. This is what I have now
Newegg.com - CORSAIR DOMINATOR 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMD4GX3M2A1600C8
and as you can see it is no longer in stock. I know I need to match up the type and speed of the memory I have in my PC, but do I need to match up the CAS latency, timing, and voltage as well? I found 3 different ones on newegg (all 3 are Corsair) that match these specs.
Newegg.com - CORSAIR XMS3 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMX4GX3M2A1600C8

These 2 are from the same "dominator" series, just a newer version than my older memory I suppose:
Newegg.com - CORSAIR DOMINATOR 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMP4GX3M2A1600C8
Newegg.com - CORSAIR DOMINATOR 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMP4GX3M2B1600C8
I'm not sure what the big difference is between these 2, but they must be slightly different somehow.

All 3 are priced closely, so that is not a concern. Any suggestions would be appreciated.

It is is always a good idea to have a matched set of memory. As long as the voltage and memory clocks (MHz) are the same, the memory should work, but tweeking will be very limited.

Shop around at other locations. Try Amazon.com if Newegg is sold out. Hell, even search on eBay.

For the price of those, you could get 8GB.
The XMS3 you listed are priced at 8GB DDR3 1600 CL9 prices.
Newegg.com - Patriot Signature 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory with heatshield Model PSD38G1600KH
Newegg.com - Mushkin Enhanced Blackline 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model 996776
Newegg.com - CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CML8GX3M2A1600C9B