Automatic downclock after first overclock

So I tried to overclock my GPU for the first ever time today. Followed detailed instructions, used Furmark and EVGA Precision to get clocks up to 625/1562/1035 from 600/1500/1000.

Just as I got into a second level of Crysis 2, my GPU downclocked to 399 and has stayed there. Did I overdo it with the overclocking? Is it entering some sort of safety mode?

Also, would my 5% increase actually have a 5% benefit in games or not at all? I noticed that my Furmark FPS went up from 9 to 11 after the overclock (in 5mhz increments of course and 15 minute tests each time) and was wondering if it was worth doing all of this for a 5-10% FPS gain in games. Or if that's even manageable.

No artifacts or crashes, just a downclock.

EDIT: IT also seemed to be downvolted from 1.0 to 0.9. It's back to normal after a restart but I must admit my heart stopped for a second when I thought I'd fried my GPU or something... Anyone else try this with a 285m? I definitely get artifacts after raising the core clock to 630 (barely noticeable but there if you look hard enough). Was wondering if it was really worth the effort. Can't afford anything new for the time being so want to get the most out of this rig. Admittedly, I think it's my CPU that needs a boost more but still.

EDIT 2: Problem solved, thanks for everyone's help!

 

That happened to my fx3700m in win7 if I overclocked it until it was unstable.
In winxp that didn't happen.
Anyway I believe you're right, it's some sort of safety mode so just don't overclock so high.
No harm done.

 

Yeah, everything's working fine now although maybe a little hotter than normal. Then again, I am running Crysis 2 which is probably the most GPU intensive game I have other than the original Crysis.

Finally using dual monitors - never had my temperature utility open at the same time as I played before so not sure if the mid 80 degree temps I'm getting for Crysis 2 are a bit much or normal... I'll try it with the stock clocks and see if it makes a difference.

 

You can simply disable/re-enable the display adapter from the "Device Manager" to get it back at normal clocks/voltage.

 

On the subject of affording something newer, the 285m has nearly the highest value on Ebay of any card with similar performance. I think you should try to sell it for about 300$ and get a 5870 or 6970m Funny fact, theres an Alibaba supplier who has them for 95$... but nobody trusts those guys.

 

Seriously? Very tempting. Would need to find a company near me that would be willing to fit it in - have no where near the relevant experience to do so myself but, at that price, I'd check it out. Am in the UK though so will see what the resell/buy price ofr individual mobile GPUs amounts to here.

EDIT: Wow, the 285m goes for £350 on ebay while the 6970m sells for £260 from the US. Might well take the plunge once my exams finish and I don't need my laptop as desperately any more.