THIS IS A WORK IN PROGRESS, I HAVE JUST PUBLISHED IT SO YOU CAN FOLLOW THE PROJECT AND TO GET SOME SUGGESTIONS.
So how much power can you get from a laptop for under 1K without compromising portability? Lets find out. (bearing in mind something simmilar from alienware is just over 2K)
(This is still under construction, next update due friday)
So what do we have to start with?
The laptop is a Toshiba Satellite A660-11M, with the core i7-720QM processor @ 1.6Ghz, 4Gb RAM @ 1066Mhz, 500Gb harddrive, and Nvidia GeForce GT330M @ 135Mhz, with 1Gb RAM. Not a bad deal for £750.
Although this is fairly fast for a laptop, there is much more to be got out of it:
8Gb RAM @ 1333Mhz (£70 per 4Gb stick)
OC CPU from 1.6 to at least 2.8, possibly 3.2
Fit water or heat-pipe cooling, as the stock cooling is not sufficient for the original speed (hits 82 degrees C)
Try to OC graphics card a bit.
Fit SSD. (60Gb Patriot inferno, 275Mb/s write speed, £100)
Construct custom cooling pad to allow constant use & house external HDD and batteries.
Yes, i know the photos go in the wrong order.
Step 1: Disassembly
The disassembly guide is not ccurrently available, so here is the only guide available so far.
Pot to put the screws in.
Small phillips screwdriver.
Small flat bladed screwdriver.
Earthed work area.
Step 2: Turn It Over
The photos say it all.
Overall, a particularly easy laptop to disassemble.
Next time: Removing the MB, Identifying the PLL, sizing up the cooling system, and why does the fan fail?
The fan appears to be ineffective as the intake vent on the base is blocked by what appears to be some flash from the moulding.
Feel free to leave any comments/suggestions.
Step 3: Identifying the PLL
The PLL or Phase Locked Loop provides the timing signals to the processor, but unfortunately it is virtually always locked at a fixed speed unless
a) your PC is fairly old
b) your PC is a top-end gaming machine
c) your PC is a custom build
Seeing as the A660 satisfies none of these conditions, we have to venture into the unknown territories of the hardware, where neither the bios or windows can impede your freedom to "fix" the clock speed.
The PLL is usually a long thin medium sized chip located near the chipset, and often has a timing crystal next to it (a rectangular silver package with round corners with some numbers stamped on the top.) See the photos for examples.
Step 4: Turboboost
While turboboost is a great little toy, it is particularly annoying to the overclocker for a number of reasons:
Core speed never stays the same- if you set the base speed to the top limit, you can get the most power under full load, but as soon as the load drops, the multiplier increases, and it crashes. However, setting the boost speed to the top limit will keep it stable, but the speed under load will not be as high as it could be. Disabling turbobost allows the processor to run at full power all of the time.
Multipliers.- disabling turboboost sets the multiplier to the lowest core speed. This is good as it allows finer control of core frequency when fiddling with the pins of the PLL.
Turboboostcan apparently be disabled in the bios.
Step 5: Power Supply
The laptop already comes with a pretty hefty 6.3A brick attached, and eats through the 48WH battery in under 1hour, and the processor is rated at 45W TDP. So doubling the core frequency will draw a huge amount of power.
The power supply is going to need watercooling.
I don't know how much the power supply can take, or what would happen if it drew too much current
Step 6: Case Modification.
Although this is not nearly as difficult to get apart as some laptops, it is kind of awkward to have to disassemble the whole thing to get at the processor and cooling system. So an important step is to cut a door in the bottom similar to the ones to access the HDD & RAM.
Also needed is an improvement in the venting, as the fan appears to have no intake (The circle on the bottom isn't actually a vent, it's just some indentations). I expect to have to replace a large amount of the underside with mesh salvaged from the deceased acer.
Does anyone have any suggestions for how to make a clean cut through the base & how to form bulges in the lids to accept larger components?
One of the main constraints on the case is the fact that it must remain looking original, so no huge cooling ducts.
Step 7: Cooling Options
This the problem with overclocking a laptop. The stock cooling is insufficient for running the original configuration at 100% load, so overclocking, and the inevitable overvolting of the core will demand a better solution.
So what needs cooling?
Possibly some of the power supply components if I overvolt the processor.
Air cooling: not enough room to fit a big enough fan, a heatsink would have to be heavily modified or custom made to even fit, and it would be incredibly noisy.
They look like one of the best options, although I don't know how well they would react to being routed around all the tight corners.
Fairly simple and effective to setup for short runs, but highly impractical for normal use.
Peltier effect coolers:
While the junction temperature goes down, it just moves even more heat about 5mm away from where it came from, while eating the battery and necessitating an even bigger cooler.
Probably the best option, allowing easy movement of heat away from many different components, including ram, with more options to the placement of the radiator(s), although a pump would need to be fitted.
Step 8: Building the Cooling System
I have considdered the use of silver for parts of the cooling loop, but at over £500 per kilo, it is a little out of budget, seeing as a tube of top quality thermal grease would be a better investment, seeing as copper is pretty close in terms of thermal conductivity.
I currently have my eye on a 6" x 1' bit of solid copper bar from which to machine most of the system, although aluminium sheet seems a more practical material for the top half of the waterblocks.
Looking at all the stuff that needs cooling, this will need a pretty epic pump to get it all working. most of the watercooling pumps for desktops seem to be about 30-40 watts @ 12v, so a brushless motor out of a VCR should give enough power to haul all that water around, while being thin enough to fit. (Actually, while thin enough to fit, it is over 3" in diameter with a very large magnet. I have extracteded another brushless motor out of a DVD drive, which should have a reasonable amount of power, providing the circuit id kept simple.
Step 9: The Radiator
At the moment, I hope to be able to fit the radiator where the old heatsink is, although I expect to have to sacrifice the rarely used CD drive to make a pop-out radiator for increased airflow. I have considered making the lid of the laptop thicker and putting a large flat radiator up there (with the back of the lid lifting off to expose it), although there may be some issues with heat between the screen and radiator, and with airflow.