Is this RAM any good for OC'ing?

cmi86

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I have a 4GB kit of OCZ2G8004GK, Its DDR2 800 5-5-5-15 @ 1.8V. I cannot get it stable anything over 800Mhz regardless of timings or voltage.
I tried 816.8Mhz W\6-6-6-18-24 @ 2.1V and I still failed within minutes of prime95, I dont know if this is normal or not but i was under the impression I was buying performance RAM that would allow me to overclock atleast a little bit, any input greatly appreciated. Thanks in advance.