Buy DDR2 now, and you wont' be able to use it in a new system. Limp along with what you have.
I was recently in your shoes. I have an E6600 on an X38 board. I was tempted to spend $100+ on a quad of some sort. On used forums Q6600 and Q8xxx go for that price. Why spend that much on something so old however when even the new 2500K is $200? I eventually spent $250 (and that includes paypal fees and shipping) for an i5 750 with a great P(?)55 board. It supports both CF and SLI. I spent another $35 on 2x2GBs of DDR3-1600 and another $30 on a hyper 212+. For just north of $300 I've got a great system that will leave a Q6600/Q8xxx in the dust.
So i was browsing in a small Computer store the other day and somehow ending up walking out with 2x1GB 667 Ram.
Have installed and seems to be running ok. Not sure whether it is in my head but general system apps and navigation seems a litter slower but then system seems to handle gaming more.
Wasn't a steal getting the 2GB but wondering now if patience should have prevailed and waited for some 800 so not mixing RAM.
Have done plenty of reading with mixed bag of results. General consensus seem to be if the timing are the same it's ok it will just run a the slower RAM speed. So no drama right? Also that 64bit windows 7 may be better with more Ram.
Then it gets a little technical for me with views saying that using all four RAM slots will use more power and drain?
Anyhow... Have ordered a Samsung Spinpoint F3 1TB after reading some good reviews.
So i'm hoping the faster, bigger HDD will make some speed improvements.
Worth keeping the 2x1GB 667 or be content with my faster 2GB 800? Views?