Mixing RAM / latency conflict?

[arambabalam]

Hi - I currently have 2 x 2 gb of this:
http/www.morecomputers.com/product.aspx?pn=TWIN2X2048-8500C5D&man=Corsair

I want to add 4gb. Can I add this:
http/www.amazon.com/gp/product/B002CHIFEC?ref_=cm_lmf_img_13

So the main difference is the latency:
5-5-5-15
and
5-6-6-18

So is it a good idea or should I stick to the same spec?

Thanks
David.

 

[arambabalam]

5 5 5 15 is very common, I would stick to this and buy used for a cheap price.
I have not come across problems mixing corsair, kingston or several other brands at these timings.(tho 1.9 volts setting was a must)
The latter set is obviously inferior lower grade ram. mixing kits on old machines is all guesswork and luck (dont spend big bucks, it might not work anyway).

Thanks a lot for the answer Tea Urchin. Is the latency the only thing that's lower grade about it or is there some other aspect? Cos it seems such a subtle difference to my novice eyes.
But I'll probably hold out for some used RAM that matches 5-5-5-15 anyway.
Unfortunatley the only used stuff I've seen on Ebay so far seems almost what you'd payfor new RAM now. I dont understand that for such old RAM.