Ram upgrade, are these compatible?

[ms5555]

I'm pretty sure this is what I need, but just running it by the friendly folks here.

What I have now:

win7 64 bit
Asus p7p55 mobo
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131604&cm_re=asus_p7p55lx-_-13-131-604-_-Product
gskill ripjaw ddr3 1600 4gb (2x2gb)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231277

What I want to add:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231314&cm_re=g.skill_ripjaws_8gb-_-20-231-314-_-Product

I think that's the exact model ram I have now, just two 4gb sticks. My mobo has slots and will support it as far as I can tell.

 

[Jameson Clark]

You shouldn't have a problem but adding ram can sometimes be weird, you just never know until you try

 

[Tradesman1]

It's a very definite MAYBE, any time you mix DRAM, even of the same exact model, it's a crapshoot, it might work or they may not play together...best to get a single set of the full amount you want, that way you have sticks that are tested to all play nice...If you have to mix sets and there's a problem, give me a shout, can often get them to play w/ voltage/timing adjustments

 

[ms5555]

Really? That's interesting, as I thought there were only issues if they were different types/brands/timings. That kind of sucks. Well, I suppose 8 gb is enough so I can just do the upgrade and then add the 4 back in if I need it later.

If I do combine them though what kind of tests should I do to ensure they are working?

 

[Tradesman1]

Could run Prime or something like that, or just use it as normal, if you get BSODs, etc then might want to try an adjustment or two