Buy Now - Clevo W870CU

By Kris Verbeeck

We got one of these. Bought it as a v3.0 Type B testing platform and it does that just fine. Truth be told, bit of an odd machine. Not to mention big, thick and heavy. And it has a battery that would struggle to power an iPod. We bought it from a Dutch Clevo retailer, XXODD, which has gone down the drain since then which is a bloody shame. As it was bought with only a tesplatform in mind, we equiped it with a sad HDD, entry level i7 and only 4GB memory. This may skew the benchmarking results a bit.

You may actually own one of these yourself without knowing. As most Clevo offerings, many boutique stores will rebrand it. Examples: Sager NP8760, Eurocom CHeetah, mySN XMG7, Deviltech Fragbook DRX and probably a lot of other.

So, we tackled the HD6970. With 28nm HKMG still a fair bit in the future, this is still a 40nm GPU. So the architecture is a lot like the HD5870. So, how did they get the performance jump expected from a next gen GPU? Easy, they dumped a lot more cores in parallel and doubled the memory to 2GB. As the HD5870 was very lean for it's peformance, power consumption 'only' rises to GTX480 levels, probably a bit lower.

HD5870 HD6970
800 Cores 960 Cores
700MHz Core Frequency 680MHz Core Frequency
1GHz Memory Frequency 900MHz Memory Frequency
1GB GDDR5 2GB GDDR5
128 Bit Memory Interface 256 Bit Memory Interface
40nm Tech Node 40nm Tech Node

So, while performance should certainly benefit from the added cores, the real treat is the doubled memory size and interface. But first, getting it up and running...

If you can't remove the backcover, find yourself another hobby. But before you do, unhook the PSU and battery.

If your machine looks like this when you open her up, slap yourself. There should not be this much dust inside it.

Unplug the VGA fan. There's a 'VGA' print on the PCB, but still: keep in mind which connector it goes in. Three screws for the fan, 4 for the heatsink and it should come right off.
Again, slap yourself if you see this. And then go out and get yourself a can of compressed air to make sure you can blow the radiator out from time to time.
HD6970 and GTX285 side by side. Notice anything odd? The ATI/AMD part is larger. So, technically, it's not a Type B module. As there's room enough inside the machine it doesn't really matter.
Moving on. The bracket stuck to the GTX285 can and must be removed. Gently wedge it loose, corner by corner. It will bend a bit, which doesn't matter. It will pull itself back in shape. Make sure the plastic liner is in tact or can be restored sufficiently. As you can see, the bracket interferes with some decoupling caps on the backside. It's not perfect, but it works. With the way the heatsink is mounted, the pressure will be more or less acceptable...
On to the next issue. Interference with the heatsink. The DC/DC coils on the card are not located where the ones on the GTX285 are which means the GPU can not be brought close enough to the heatsink.
Some more. Best is to mark the interferance you see on top and left and righ. Where the marks come together, you know where to remove some heatsink material.

A Dremel works pretty nicely to make the required modifications but pretty much any tool will do. However...

CAUTION: on the backside of the card are the heatpipes. While they look like solid copper, they are not. Pinch them, the fluid inside will drain and the heatpipe will be useless.
 
The aluminium shell around the card is required to get the card to the correct height and provide support. With the HD6970 being taller, a modification is required. With the alu being quite thin, a simple plier will do.
 

On to... sigh... the next proble. The W870CU comes with a 120W PSU. When doing the first benches, the computer cut out. Or rather, it did not. It kept running while the screen went black. The first possible culprit is obviously temperature... This led me to modify the heatsink a bit more untill I was certain the core was in perfect touch with the heatsink. Basically, if the core leaves a perfect heatpaste print on the heatsink, you're set.

That didn't work.

The core temperatures before the shutdown were low enough not to warrant such issues.. At this point, I ditched GPU-Z and moved to HWInfo. The difference is HWInfo adds memory temperature information. Which skyrocketed rather fast. Makes sense. Double memory density and all.

So, I removed the silicone based memory heatpads and moved to our 17W/mK high grade pads. Temperature was under control. Yay!

Or not.

The shutdown still occured.

So, next possible culprit: the PSU. Rated for only 120W, it's probably overloaded.. Dragged out the bench power supply. Unfortunately, it won't yield 20V but at 16.4V, it took a massive 140W, or almost 20% more than what the PSU is rated for.

And then it shutdown.

So, we got a 20V PSU.

And then it shutdown.

So, we turned it up a bit, up to 22V. If the shutdown was caused by overcurrent protection on the motherboard or MXM card, this would give 10% more headroom or 30% against the 16.4V PSU.

Still, a shutdown at exactly the same moment.

 

At this point, I could see two more reasons why things went wrong. Either another, non-monitored component on the card was going in overtemp protection or the card was just bad. It had to be components that consume a fair bit of power while being 'smart' enough to go in shutdown.

This excluded the FETs (first sign of those overheating would be that they fell off the board or went up in smoke, EEPROM, Crystal, logic... But not the DC/DC controllers. So we took the silicone pads we got from the memory and added them to the indicated parts.

As we were getting pretty damn tired of this, we replaced the HD6970 at the same time. Not the best for diagnostic purposes but it beats tossing the whole thing out of the window.

AND THAT FINALLY DID THE TRICK!

We ran Vantage in performance mode. With the GTX285 we got P6979. The HD6970 logged a rather impressive P10927! Truth be told, the GTX285 score seems a bit low so we'll revisit that with better drivers but regardless: P10927 *is* an excellent score. As Vantage yields a hybrid CPU/GPU score, we can also tell you GPU1 went from 17,14 to 33,08 fps and GPU2 from 15,85 to 31,19.

So, what does all this mean? In the end, we also ran full benches with the 120W power brick, which worked. So, no worries about the PSU, memory heatpads, cooling at the back? Not exactly. We could go back and see what is required to get it running and what not. See if it was the card or the lack of cooling at the back. But we won't. Simply because even if it is not required it is good practice. This, including a more powerfull PSU, is how it should be done!

 

The below link may only be used for the Clevo W870CU notebook. If it is used for any other platform, we reserve the right to refuse returns or warranty. You will have to rework the heatsink to fit the card.