Hi, hope someone can help.

I have a HP Z400 workstation - 4 Dimm slots, currently using 2x2G ram. I'd like to upgrade to 8G and I'm confused by RAM compatibility. According to HP manual I require ECC Unbuffered RAM. That's easy enough.

I've looked up Kingston and this is the list of compatible RAM they list for my workstation.
http://www.kingston.com/us/memory/searc...ion&Model=55069
I've found a site in the UK that sells a compatible single 4G stick for 31 pounds.
http://www.ebuyer.com/244940-kingston-m...3-kth-pl313e-4g

I've also found this set of 2 x 4G Kingston Ram but it is cheaper. The only thing is, this set was not on the compatible list and is a different part number.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820139262

However, specwise, I don't see any difference other than the more expensive one is system specific and the cheaper one has thermal sensor. They are both ECC unbuffered DDR 3 1333 (PC3 10600) Ram, CL9 1.5V. Is this RAM compatible with my workstation? Or should I stick with what is recommended?

Thanks. Yes, its XP 64 bit.