Question regarding an older i7...

I've had a few... concerns about the performance of my CPU. The temps are always rather high and I'm unable to overclock worth a damn without causing my machine to BSOD. Currently if I so much as breathe on it wrong, the system brings up an error that only points to the CPU being the culprit.

So my question is thus:

Since the CPU seems to be a rather big problem for me, temperatures and whatnot, would it be a significant downgrade to drop to the 840QM from the 920XM?

Core Temp regards my CPU as a 62w TDP, if that's true, then I'm already at a disadvantage with this chip if the performance gain, over the 840QM, is only 10% (as I was led to believe). I'm just tired of this machine running so damned hot all the time. The GPU I can understand, as I had the GTX 470 in my last desktop so these temps aren't surprising to me, but the CPU constantly running at 85*C just seems... too hot.

The above question remains to you all.

Appreciate any help on the matter! ^_^


-Imglidinhere-

 

Well....

I am on 840QM and run 41-45C idle and about 68C load.
To answer your q (the bold bit) if you plan not to overclock then the 840QM is fine and would compare favorably with the 920Xm at defaults without overclock.(See second link below benchmarks at default without o/c on 920xm shows equality with 840QM)

I would love to trade my 840QM for your 920XM and see what all the fuss is about. Yikes 85C what multipliers are you running? Have you gone back to disabling the overclocking in BIOS and seeing what temps occur on the 920XM?
Could be in desperate need of a repaste possibly....but...would dearly love to try your 920XM heheheh. :thumbsup:

Here is some links to important figures which answer your questions with detailed benchmarks....as I plan to overclock the cpu I use this as my reference to upgrade mind you the 840QM is no slouch either and runs very kewl.
http://forum.notebookreview.com/sag...0qm-940xm-vs-720qm-820qm-920xm-benchmark.html
http://translate.google.com/transla...re-i7-740qm-840qm-940xm-prozessoren-nkmo-1171

 

Its a really, really, really bad idea if you are buying. The 45W TDP is extremely restrictive for the i7-840qm, you'll never see the turboboost since you cannot alter the TDP/TDC rating so your performance is marginally better than the i7-720qm. I agree, any temperature over 80 degrees for extended periods is too hot, my old ASUS n61jq with the i7-920xm used to be in that temperature range too, and it died from fried vRAM which sat underneath the hot heatpipes.
If you are worried about temperature, the only thing I can recommend is sidegrading to an ebay OEM i5-580m or i7-640m, you'll lose about 20-30% peak performance in multithreaded operation but you'll drop temperatures by at least 10-15 degrees.

 

I'll be upgrading to the 7970M, eventually so... if you're not seeing any significant bottlenecking going on, then I think I'll be good with the 840QM. I wouldn't mind swapping out. I'd be without a PC for a while during the process though.

The multi I run is x24 but I've modified the Throttlestop to work with 80W & 62A, so it peaks around 2.66GHz before the TDP is reached. i7-920 (LGA 1136) levels from what I've seen. It's pretty nice when it's used, but the temps just... they scare me when I see what they run at pushed like this. I've seen it break 90*C.

I'd much rather use a cooler CPU if the performance difference isn't that great. My heatsink is also kinda dead too, from what I've been told, since others have been able to reach upwards of 3.6GHz and not break the 90*C mark. o-o That and my entire system is just freaking out, so it could be a combination of things right there now that I put a bit more thought into it. I'll toss you a PM about it.

The multi-threaded performance is what I'm counting on. I'm gonna be grabbing the 7970M eventually, so it's required to keep up with THAT monster. Otherwise, I would just go for the i7-640M. Believe me, that was the first thing I was looking at.

 

Why don't you just run the 920xm at 840qm speeds? Also, using a 7970m with an i7-640m, the CPU will be the bottleneck.
In fact, I think even the 920xm at stock speeds will bottleneck it.

My advice? Mod the heatsink (I say this to everyone, lol) and repaste the 920xm, then run it at stock or 840qm speeds...

 

You should just down clock it, repaste and get a good laptop cooler.

My 740qm idles at 35 Celsius and holds 60 under full load.

 

What can you do to modify this heatsink though? I've not seen any mods created for added cooling. o_o;

That and I use the CM U3 cooler. I'll gladly do such if I can resolve this easily.


Quick edit here,

Why wouldn't it keep up with the 7970M? It keeps up with dual 6970Ms just fine. I was under the impression that the 7970M is exactly 100% faster than the 6970M, and if Vantage scores are to be followed, then I should be good... unless I'm missing something?

 

The bottleneck comment refers to the fact that high-end graphics cards can process more information than central processors, since they have many more processing cores, much higher thermal dissipation, and their own faster dedicated memory. As such, the high-end graphics cards are the most powerful component in a system and everything else can be considered a bottleneck since it reduces the realized potential of the graphics card.

While this is technically accurate, in practice I find it rather silly to be concerned with such things on a mobile system. There's a limit to how far notebook computers can be upgraded, and labeling a fully-upgraded component a bottleneck is a waste of time and thought.

 

85 under load is not hot though..

 

If the A10-4600m worked about 27% slower than the 3720QM (both with the 7970m - from here ) then I'm pretty sure you should be fine with the 840m. However, like others have suggested, you could try cleaning out the ducts and reapplying some paste and may be even downclocking your CPU before you downgrade?

 

imglidinhere, what thermal paste are you using?
When I put my 7970m in I used some brasso to polish the copper heatsink and then isopropyl afterwards. Aside from that, along with a good thermal paste(Strongly recommend ICD7), then you should be fine with your temps and 920XM. I for one would not lose that cpu it's a keeper and your issue has more to do with setup.

Good luck.

 

This, if you're hitting 85C under full load, there shouldn't really be any problems. It's not cool, but you're still a good 15C below Tjunction so nothing to worry about really.

 

85*C at STOCK is what I'm saying. It hits 90*C+ when overclocked and I can't do anything about lowering that temp.

I see most users running 75*C or less with this same setup. I've repasted, changed out the heatsink for a new one (that helped a bit in the past, since it would just overheat regardless), AND tried to throttle the TDP usage in throttlestop.


I had an idea though. Not sure if this would work, but it's been bouncing around in my head for a bit. Since these blower fans have two intake sides, could you just block the side that's right next to the hotter component and leave the bottom intake open?

 

Is that 920xm a ES cpu or OEM. I still have an Asus g73jh with that processor , ES version, in my closet that gets about the same temp on stock speed. The top overclock was about 2.5 before it started to get over 95C. I repasted that cpu so many times that I dont bother with it anymore. Its being sold on craigslist this week.

 

So there is a difference between OEM and ES?

 

Hmm there is no noticeable difference between OEM and ES usually. My ES right now is idling between 35-40C (naturally fluctuates) and I run 24/7 @ 23/23/25/27 multis at 85W tdp. I haven't repasted it in at least a year! Played many new games since then including Crysis 3 and FC3 along with plenty of RTS games so it has been well used.

If the 920xm is properly re-pasted and the heatsink and fan is dust free then in an M17x R2 the temps should be at least as good if not better than my own!

edit: oh ya forgot to mention this is in 25C ambient in my air conned flat (summer in Japan!)

 

Point is if 920xm is that hot, downgrading is not going to help much. The chance of a defective cpu is really low.

 

Well, the 7970m in question is as fast or faster than a desktop GTX 570 (which I find really impressive). The 920xm Clarksfield will not be able to keep up with it in the sense that the card will finish its work and will have to wait for the CPU to catch up.

I.e. any stutters, low framerates and whatnot will be caused by the CPU. Then again, that will only be the case if the game actually fully uses all the CPU threads - I don't know, something like Crysis 3 and newer games?

Unfortunately, even a heavily overclocked 920xm doesn't reach 3720qm levels. Even the 2720qm is roughly twice as fast as the 920xm (and the 3720qm is faster).

@imglidinhere I looked at the heatsink - it's this one, right? It should not be heating up like that, something is really wrong. If it's not the thermal paste, maybe it's the heatsink itself? A new/used but good one from eBay might work then...

 

That's the one. Bought a new heatsink about a year ago and it fixed the problem of overheating to the point of shutting off, but the new heatsink gets these temps.

I'm starting to think it might be an ES chip. I know it would say it, but this thing just does NOT stay cool. Even CPU-Z rates it at a 62w TDP when the OEM models are rated for a 55w TDP. I just don't get it...

 

Just a thought - it could also be a motherboard issue, providing more voltage than it needs - in which case, any CPU would heat up way more than normal temps. Did you try another processor?

Alternatively, the CPU itself could be damaged (from too high of an overclock or temperature, for example), requesting more voltage than it requires...

Can't think of anything else, really, since even ES CPU shouldn't heat up that much...