My Phenom II 945 has marks on it - should I lap?

When I first open up a new CPU, I make sure it's not dirty... if it is I'll use ArctiClean. Anyway, I noticed how much chip had little grooves and stains on it. I even rubbed my nail against one of the grooves to make sure it wasn't a reflection, and sure enough it wasn't smooth

Seriously, does this need lapping? Should I waste my time doing that? I've lapped heatsinks MANY times back in the Socket A days, but I've never lapped a CPU. Is it just as easy and can I use water on the sandpaper?

Look at the stains on the top-right of this pic (those circles) - YES, that's how it came from factory:




You can really see the dings/grooves on the bottom and some to the left (just to the right of the white out mark I put)


Similar view as just above

i wouldnt lap it untill your sure your not sending it back, but if it were me i'd probally return it. when your payin $200 it better be damn near perfect

Niku-Sama said:

i wouldnt lap it untill your sure your not sending it back, but if it were me i'd probally return it. when your payin $200 it better be damn near perfect

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It's been just over 30 days that I bought the CPU from NewEgg. I'd probably have to send back to AMD, but would they even cover that... might not be worth the hassle. =/

It probably wont hurt to leave it the way it is, make sure it works before you lap it (if you decide to)

also lay a strait edge across it to check for flatness, the ihs on my 940BE was concave and lapping dropped the temps by ~6C. so lapping may be worth it if you plan to really push your oc.

Godman I love you... but you've lost your mind.

You're saying there's a microscopic scratch somewhere on the CPU... that I can't even seen in your blown-up images (you've also rubbed out the serial number... afraid somebody's gonna claim your warranty?)

I'm assuming the temps are absolutely normal... and... why the hell does your brand new chip have grooves and stains anyway? (I don't see the grooves... but I see the stains.)

Did you buy it open box? (Aren't new AMD cpus like $20 now or something?)

If you bought it new, then 30 days be damned... just call-up newegg and explain the situation.

That certainly is unusual.

New? Why would you have to contact newegg after 30 days? If it was OEM than that explains the dirt I suppose. Personally would not ever buy OEM from newegg, because they do not really discount them well enough over retail, and sometimes even charge more!

If it was me? I would probably run it anyway, but shoot AMD an email about it nonetheless.

If you do decide to lapt it, dont use water, just some high grit paper is enough. (You do not have to get too excessive, 1200 should be plenty fine enough (I usually start with 800 and work my way up to 2000 on the rare occasion I do lap a cpu)

rainless said:

Godman I love you... but you've lost your mind.

You're saying there's a microscopic scratch somewhere on the CPU... that I can't even seen in your blown-up images (you've also rubbed out the serial number... afraid somebody's gonna claim your warranty?)

I'm assuming the temps are absolutely normal... and... why the hell does your brand new chip have grooves and stains anyway? (I don't see the grooves... but I see the stains.)

Did you buy it open box? (Aren't new AMD cpus like $20 now or something?)

If you bought it new, then 30 days be damned... just call-up newegg and explain the situation.

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Yes, there are scratches. I know this kind of stuff affects cooling, though... I mean, I wouldn't spend an extra few hundred dollars to get watercooling if I didn't care for a few degrees.

Yes, I bought it brand new - why didn't I return it right away? I figured this may have been normal, and was EXTREMELY EAGER to get my first quad-core set up.

Neur0mancer said:

That certainly is unusual.

New? Why would you have to contact newegg after 30 days? If it was OEM than that explains the dirt I suppose. Personally would not ever buy OEM from newegg, because they do not really discount them well enough over retail, and sometimes even charge more!

If it was me? I would probably run it anyway, but shoot AMD an email about it nonetheless.

If you do decide to lapt it, dont use water, just some high grit paper is enough. (You do not have to get too excessive, 1200 should be plenty fine enough (I usually start with 800 and work my way up to 2000 on the rare occasion I do lap a cpu)

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You sure not to use water?

You don't need to use water to lap the CPU. I don't even use water when lapping a heatsink.

Only thing to watch out for when lapping a phenom are the pins, it's really easy to bend one since there isn't much room to grip the cpu without contacting the pins.

I have no idea how you start out lapping at 800 grit Neur0mancer, that must take forever. I generally start out at 150, then 400 grit, and stop at 600.

Lapping it might help. I know the phenom II's have a pretty uneven base. When I lapped my 720 the outside edges were raised up quite a bit more than the center. Starting out at 800 is nuts. Starting with 300 grit took forever to level out the ihs.

I'm probably going to sand with 220, then 300, then 400, then 600, then 800, then 1000, then 1200.

I feel like it's similar to a car's engine/transmission. When you have a 5- or 6-speed, it usually accelerates faster.

Take a go-cart for example (yes, I have one that I used to ride when I was a kid, probably collecting dust now). It was one gear, probably did 20-25mph. It was one gear... I felt like it would have been much quicker if it was manual.

Anyway, I'm sure you get the idea, but I'll figure it out. I'm still debating on lapping or not, but my idle temp is freakin' 48-50C @ 1.50vcore on water, while just browsing/emails!! When I turn on the AC on a tower fan in the room to circulate air better, I might get it down to 43C, maybe a bit less. I could have sworn it used to be a bit better, but those have been the temps lately...

Lapping it will certainly give you lower temps. If you're willing to put the time in, and don't mind voiding your warranty then go for it.

downer said:

Lapping it will certainly give you lower temps. If you're willing to put the time in, and don't mind voiding your warranty then go for it.

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Not to jinx myself, but I've yet to have a CPU need to be sent back to the manufacturer...

g0dM@n said:

Not to jinx myself, but I've yet to have a CPU need to be sent back to the manufacturer...

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Me either

Of course some of my cpu's have died of unnatural causes.

I would just leave it. Lap it if you want lower temps or higher oc's, but other than that, I have plenty of those dings on my cpu with no problems.



Middle, middle-left and the bottom all have noticeable scratches and wah la! It runs just fine .

It's still BS... There's no excuse for AMD to be shipping CPUs with dings, scratches and stains on it. I'm a little upset about that.

Oh, I definately agree with you, I am just saying, I had scratches on mine and it's nothing I lost sleep over.

downer said:

You don't need to use water to lap the CPU. I don't even use water when lapping a heatsink.

Only thing to watch out for when lapping a phenom are the pins, it's really easy to bend one since there isn't much room to grip the cpu without contacting the pins.

I have no idea how you start out lapping at 800 grit Neur0mancer, that must take forever. I generally start out at 150, then 400 grit, and stop at 600.

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Yah it does take a while but I do not try to remove much material just get it flat.

One core 2 i dropped to 400 because those IHSs were seriously whacked. But normally, 800 is fine. and yes it does take a while (20 minutes or so)


If you do start with a lower grit paper, I hope you are using a bolt through heatink and not the AMD clip.

Neur0mancer said:

Yah it does take a while but I do not try to remove much material just get it flat.

One core 2 i dropped to 400 because those IHSs were seriously whacked. But normally, 800 is fine. and yes it does take a while (20 minutes or so)


If you do start with a lower grit paper, I hope you are using a bolt through heatink and not the AMD clip.

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Are you sanding down to bare copper? If you're trying to make the IHS flat, you're going to remove just as much material regardless of what grit you start at. There is no way you are getting an IHS flat with 20 minutes of work at 800 grit.

I have used a lapped Phenom with the stock heatsink and retention clips without issue. The fit was still tight, and contact was good.

I don't mean to jump on you Neur0, just want to share my experiences with the CPU's I've lapped.

downer said:

Are you sanding down to bare copper? If you're trying to make the IHS flat, you're going to remove just as much material regardless of what grit you start at. There is no way you are getting an IHS flat with 20 minutes of work at 800 grit.

I have used a lapped Phenom with the stock heatsink and retention clips without issue. The fit was still tight, and contact was good.

I don't mean to jump on you Neur0, just want to share my experiences with the CPU's I've lapped.

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I do somewhat agree. The reason I can't say I agree certainly is that I have never lapped a CPU before - I've only removed IHSs and lapped heatsinks. With my lapping experiences on heatsinks, when I start with a lower grit sandpaper like 220grit, it makes my life much easier. That's why I bought the course and fine lapping kits from EasyPCkits.

While I agree there shouldn't be as much defacing as there is I try to look at the big picture here. The Phenom II is over 66k sq mm in size (258x258mm I think?). The scratches you're talking about are maybe 2x100mm total, maybe? That's only 0.3% of the cooling surface. And we're not really talking NO cooling in those areas, just less cooling since the TIM doesn't conduct as well as copper. So the real impact of those scratches on cooling is virtually nil - even with water. I can understand your concern and I'd certainly be a little miffed if I were you but I just don't see an issue as far is cooling is concerned.

I might be tempted to take some sandpaper to those stains, though. Since we have no idea what they are there actually could be almost zero cooling there (though that's doubtful but who knows?).

More important would be any concavity of the surface, which might have detrimental effects over a large percent of surface area. IIRC, the Fusion is slightly convex but it still shouldn't be taking up slack for the IHS being concave. The convex surface is there to create higher contact pressure near the center of the CPU and increase heat transfer in that area. Given that, and the obvious fact that the CPU has been "manhandled" in some way, I would take a close look at IHS flatness in this case. Just my $0.02 ...