Thinkpads Forum

Hi,

Given that W710(?) is coming out soon and the prices of W700 will be dropping further, I was wondering whether it would be possible to put a Quadro FX3800M in a W700 machine (since the GPU in W700 is not soldered to the mobo as in earlier ThinkPad models). So, guys, what do you think?

Interesting question. It's not likely, because the edge connectors are different:

http://forum.thinkpads.com/viewtopic.ph ... 68#p563968

Plus, even if you could, you might not want to, as the 3800M can draw as much as 25 Watts more power than the 3700M. The 3800M is almost an overclocked 3700M, giving you a third more max performance in exchange for a third more max electrical power.

The interesting thing is the processor power budget of the new W-series machines:

W500: 35W max CPU TDP + 30W max GPU TDP = 65W max processor TDP
W510: 55W max CPU TDP + 35W max GPU TDP = 90W max processor TDP

W700: 45W max CPU TDP + 75W max GPU TDP = 120W max processor TDP
W701: 55W max CPU TDP + 100W max GPU TDP = 155W max processor TDP

(the 55W max CPU TDP is for the new quad-core i7-920XM CPU)

The processors don't draw anywhere near that while you're performing mundane tasks, but can draw close to that while playing 3D games, for example. And virtually all of that power is converted into heat, which must be dissipated.

So you might ask yourself: the new machines have significantly better cooling systems, right? That's not clear. The W510 doesn't appear to. It appears to have the same size fan, with the same number of blades (in Hardware Maintenance Manual diagrams), and the same fan motor (according to sparepartswarehouse.com), larger vent on the side, but smaller one in the rear. Plus there have been reports of W510 machines overheating while playing DVDs or intensive 3D video games, then spontaneously shutting themselves off:

http://forums.lenovo.com/t5/W-Series-Th ... d-p/211509

And one guy's W510 essentially self-destructed while playing a DVD when docked with the display closed:

http://forums.lenovo.com/t5/W-Series-Th ... d-p/214788

Lenovo temporarily issued a BIOS update that apparently throttled back the GPU (producing stuttering graphics, according to users, instead of overheating and immediate shutdown). The update appears to have been temporarily pulled due to it causing a Microsoft authentication problem for Windows.

So are these problems just isolated flukes? If not, can they simply be fixed by throttling back processors, while still providing adequate performance? If so, will users obtain the full benefit of the higher-performance and more power-hungry processors? Will the W701 have a substantially enhanced cooling system? How? Beats me. I guess time will tell.

In any case, I don't think that Lenovo is going to be the only manufacturer having these problems.

Thanks a lot for your extensive reply! You are right about the connectors, judging only by the pics on the nVidia website it really seems like there is little chance for the GPUs to be interchangable. I am not sure though whether one can draw accurate information from those pictures.

The compatibility issue put asside, I think, under some assumptions W700 might be able to handle all that heat. It is all about those excessive ~25W, so here is something:

1. W700 is quite big and has two fans, so there is some chance for it to be able to handle more than those 120W. Given all the heat it is supposed to handle, it might have been very well designed with some "overheat" in mind. Or perhaps W701 will be using the same cooling system as W700, which would mean (best scenario case) that W700 is indeed designed to handle "overheat". Ok, so far with unbased speculations

2. Intel C2D T9900 (3.06 GHz, 6 MB L2, P Socket) has TDP of 35W and Intel C2D P9700 (2.8 GHz, 6 MB L2, P Socket) has TDP of 28W. The latter would give spare 17W.

Performance-wise, according to notebookcheck 3DMark06 benchmarks Quadro FX 3700M reaches about 11k points, whereas Quadro FX 3800M reaches about 13k points. I am not sure whether such performance difference really justifies the additional 25W heat output (given the anyway great performance of FX 3700M). On the other hand, 2k points can be considered as a whole additional GPU

Cheers,

Marin

I think the trend we're seeing, for both the CPUs and GPUs, is to minimize the amount of power at idle and when performing minimal tasks. That's great in terms of improving battery life. Your octocore laptop will draw the power of a netbook when you're surfing static web pages or doing word processing.

It also means that, when on battery power alone (and on AC power alone), that octocore laptop will have the max performance of perhaps a dual-core laptop.

But when you're on AC power AND you have a fully-charged battery, then you'll have full octocore power (just as many current ThinkPads only achieve full performance when they can draw power from both sources). But you'll only be able to achieve that performance if the cooling system can dissipate all of the resulting heat. That's where the question mark is right now, particularly with the Calpella quad-core processors in 15" laptops. And with the higher-clocked 128-core 3800M in the W701.

You can run the fans at full RPM earlier and more often. But you still have to deal with the steady-state condition of the CPU/GPU running at full speed for a sustained period of time, while playing 3D games for example. And if you can't dissipate that heat, then you'll have to throttle back the processors, meaning that you won't be able to take advantage of their full performance.

So that may mean that you've just wasted the extra money you spent on the extra-20%-faster processor, for example.

Like you say, neither of us knows at this point whether the W510, for example, can handle the fastest processors that Lenovo offers for it. Or whether the W701 can handle the fastest processors Lenovo will offer for it. And I've seen reviews where people say their 15" quad-core laptop runs cool, but then they've never tried to push it's performance limits for any sustained period of time. So they have no idea of how much heat it pumps out in those conditions. The quad-core processor is not all that useful or cost-effective, if all you're going to do is word processing and light web-surfing.

Actually, by the time octocore mobile processors come out, they'll be using smaller chip design rules, so their circuits will be smaller and they'll have better performance per Watt. Another trend we're just starting to see is offloading of processing power, even for video games, to the cloud. So you may subscribe to a supplementary online computing service, to which you'll hand off a complicated piece of code that you want executed simultaneously on 256 high-speed processors. You'll get the result back in few seconds, which will make your netbook look like a super-computer.

Well, actually, your netbook won't even look like a netbook. It'll instead be a thin piece of plastic that you carry around in your pocket and unfold on the table in front of you. Or it will be mounted on your sunglasses, and will project its display directly into your eyes.

And that isn't too far off. We'll wonder why we wasted our time with those big clunky netbooks and iPads. (In your 60-something haze you'll wonder, iPad... was that the name of a computer, or was that a feminine hygiene product?)

BTW, I see that the W701 is now apparently available at www.lenovo.es. It's listed in a fixed configuration with only 2 GB Memoria.

I think you are going a little bit off topic now

Anyway, my point was only that if there are no compatibility issues, W700 might well be able to fully utilize a Quadro FX 3800M in a configuration with a C2D P9700 CPU. The P9700 seems to be the best theoretical solution as to the 4-way trade-off CPU/GPU heat/performance under the given circumstances.

I think the only fly in your ointment is that you can't necessarily save some heat on the CPU side and give it to the GPU in the W7XX.

That's because the left fan is attached to the CPU (and chipset) via one heatsink. And the right fan is attached to the GPU via a different heatsink. So the processors share the same enclosure and draw power from the same source, but their cooling systems are separate. Here's a nice photo from tinkererguy that illustrates the point:

http://picasaweb.google.com/tinkererguy ... 0423539746

On the W5XX, the two processors share the same fan, so that's a different story.

However, one thing you could do in the W700 is pop in a new GPU fan that simply has more blades. That way, you move more air per revolution (and more quietly, too), and thus more air at any given fan RPM. But there's a limit to how many blades you can effectively put on a fan, and Lenovo may have already maxed out in that regard. At that point you're probably talking about tradeoffs between airflow, blade materials, weight, cost, loading on the fan motor, etc.

BTW, the idea of using the P-series CPU with a high-powered GPU is a good one. The reason is that it gives you a low power requirement for run-of-the-mill operations. And the 128-core NVIDIA 3700M/3800M GPU is so much more powerful than any of Intel's quad-core processors, and it can be used for general-purpose computing.

So if you have an extremely computationally intensive task to run, you can code it up to run under CUDA or OpenCL on the 128-core GPU. We should be seeing more commercial software taking advantage of this capability as time goes on. For example:

Company puts NVIDIA GPUs to work cracking wireless security

Mathematica Users Get 100x Performance Boost From NVIDIA CUDA

That's pretty astonishing stuff.

QFoam wrote:I think the only fly in your ointment is that you can't necessarily save some heat on the CPU side and give it to the GPU in the W7XX.

And if it was just the only one... At first I thought that the cooling system would be integrated, i.e. that both fans serve both the CPU and the GPU, but from your picture it becomes apparent that they are pretty much separated from each other. You are probably right about Lenovo maxing out the cooling capabilities. W701 will be most likely using more powerful fans to dissipate all the heat, but if the inner design stays the same, those fans may turn out to be backwards compatible with W700.

QFoam wrote:BTW, the idea of using the P-series CPU with a high-powered GPU is a good one. The reason is that it gives you a low power requirement for run-of-the-mill operations. And the 128-core NVIDIA 3700M/3800M GPU is so much more powerful than any of Intel's quad-core processors, and it can be used for general-purpose computing.

That is exactly my idea! Keeping some reasonable CPU while maxing out the GPU. Many multithreaded algorithms are suitable for CUDA and will thus be ported to it sooner or later. And for those that can not be ported, it seems some decent CPU would suffice. However, the CPU should not be too "slow" either, because there are tasks that, even though mainly executed in the GPGPU, also give good load to the CPU (most common example are games), so at some point the CPU must keep up with the GPU too.

Soon there will be mathematical software, archive software, audio and video converting software, that will be able to heaviliy utilize GPGPU. Regarding wireless security and GPGPU, pyrit seems to be the biggest project here and so far looks quite successful...

Nevertheless, one should not overestimate GPGPUs. First of all, it will take a while for this technology to mature, and there is plenty of code to be written and debugged for that. Also, the platform itself has plenty of limitations as of now, i.e. despite what I am saying above, there are plenty of algorithms that cannot be ported to GPGPUs. Maybe, these limitations will be resolved with future developmens in the (GP)GPU architectures. This, however, remains to be seen as well.

BTW, kind of related to this discussion is Tilera 100-core CPU. More about it can be found here and here. It can deliver 4x the performance of the current Intel Nehalem CPUs for 4x less the power consumption, and its maximal power consumption is about 55 W (under full load, when it completely and totally outperforms any Nehalem CPU by light years). We may be seeing these in future ThinkPads in 2011 (provided the ThinkPad brand still exists there)

Marin85 wrote:BTW, kind of related to this discussion is Tilera 100-core CPU...

I like that. If they can bring their processors to market this year at that performance/power/price point, it will be quite an improvement over what we have now. It'll be interesting to see how they do. They have at least 40 patents pending, which is a good sign, and seem to have good expertise. Perhaps someone like Intel or Apple will buy them out.

I wish they were publicly traded.