Mixing 4-4-4-12 and 5-5-5-12

[Xanager]

I have been running Vista with 2GB of Corsair 4-4-4-12 DDR2 800 (http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034)

I recently ordered another 2GB, but ordered a slightly different type by mistake. I purchased 2gb of Corsair 5-5-5-12 DDR2 800 (http://www.newegg.com/product/product.asp?item=N82E16820145590)

My mobo is an Asus P5N-E 650i, and because it is very finnicky with the memory, I have been using manual timings with the 2GB, set at 4-4-4-12 22 2T. I put the other 2GB in for a total of 4, and so far it is working fine. Will I see a performance hit by doing this? Should I underclock to 5-5-5-12, or keep it at 4-4-4-12 as long as there are no stability issues? One set of RAM is 1.9V and one is 2.1V. Don't know if this makes a difference either. Thanks!

 

[JuiceJones]

They seem pretty similar, possibly the same modules, with the only difference being the CAS4 sticks rated at a higher voltage to achieve CAS4. Simply set all the sticks to run at 2.1V and you will probably be able to run the CAS5 sticks at 4 stably. If problems occur, just take the small performance hit, like 5% worst case, and run all at CAS5.

 

[eric54]

2.1 is the maximum voltage. It really isnt set in stone, as long as your system is stable you're golden. Just set the new pair to 2.1v with 4-4-4-12 timings. It should be stable, but if you run into issues put em to 5-5-5-12. Its not a huge performance loss, and you're likely not to notice.

 

[Xanager]

Sounds good. Thanks so much for the help.