Low profile 6750...

Soldato
Joined
17 Aug 2009
Posts
10,910
It was demoed as a 5750 but when the great renaming happened all the 5750 and 5770 cards became 6750 and 6770 cards... trolololo etc...

So now it's a 6750.

http://www.powercolor.com/Global/products_features.asp?id=363

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Costs ~£134 to get one shipped over because no retailer this side of the pond is insane enough to think they can shift a low profile double slot gaming card.

I'm musing over it though. Just for the hell of it.

This is my ITX as of yesterday:

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It's slightly longer than the 5570 currently in there but it will fit lengthwise.

Width wise I have a theory. Yes the 6750 is a double slot pig but the fans probably take up most of that. With the fans and shroud removed and maybe a little trimming of the heatsink it should pop in there with no problem.

Instead of its own fans it uses the airflow from the PSU to cool it, same way a number of CPU coolers use the PSU instead of a fan for cooling.

To improve airflow in the case I'd have to put some effort into shortening the PSU cables and drilling some vents in the top right area for the PSU to breathe more easily.

Back to musing over the value of spending £134 for the amusement of packing a 6750 into a tiny case...
 
Ordered it from the states.

So sometime in November or December there's going to be an update in which I successfully mod it to fit my case.

Or there's going to be an update where I was unsuccessful in modding the only low profile 6750 in the country and now can't sell it either because I've vandalised the cooler.
 
Right.

It's more or less as expected but it wouldn't be modding if everything was exactly as planned.

It currently has a full height bracket on but it comes with a double slot half height bracket which I may saw in half to get the single slot bracket I want.
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Without the shroud and double fan arrangement you can see how the fins are laid out.
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The 5570 is in the top and the bottom shows the 6750 held above it for dimension checking.

As you can see there's about 1mm of clearance between the lower level of fins and the PSU. The three raised sections will have to be lowered to match.
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I've also ordered a slim 80mm x 15mm 3100rpm fan as a possible upgrade to the one currently in the PSU.


This is something unexpected, I didn't realise the 5750/6750 needed a power connector. Turns out it uses 86W which is 11W more than the board supplies.
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As you can see that doesn't help with the length issue since there isn't physically space for a connector.
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Nevertheless a 6 pin is merely 12V and Ground which essentially means if I can get two wires in there, it's sorted.
 
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Well it's still in one piece :p

Unfortunately that includes the heatsink.

*makes feeble excuse about not feeling well*


Actually, cutting the fins should be the least of the problems.

All the wiring for the front USB, audio & switches is right where it seriously gets in the way and I cannot physically put the card in because the back of the USB stuff is blocking it.

It's not beyond me to move the ports and switches to the other side but it would be a major pain in the ass.

Need to plot more butchery on the case...


*Edit:

See what I mean - remember the PSU cables still need to get round the end of that card.

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**Edit:

Nvm all that.

I've had a thought.

The USB and audio ports at the front are redundant really. the ITX board comes with 6 USB on the back and it's not exactly a crippling stretch to plug in headphones 15 cm further round the back of such a small case.

So with that in mind I unscrewed the module which carries all of that.

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And the gap where it was now gives room to route the thick motherboard cable bundle into the space behind the front bezel, past the card and another slot can be cut out for it to come back in to plug into the board.
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An added bonus is those infernal USB and audio header cables are now no longer going to be in the way of anything.

Just need to consider how to cover up the holes the missing ports will leave, maybe epoxy a slab of black plastic in and paint it up.
 
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Ok its done.

It's in and by **** was it a total brass stud to install. If I ever upgrade I'm likely to sell the entire thing as a bundle than try and remove it for individual sale.

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Not firing on any GPU cylinders as yet. I'm fiddling a 6 pin connector which needs to be spliced into the 12V and ground cables. But the rest of the build is operational.

3.4GHz i3 2130
8GB DDR3
128GB SSD
320GB HDD
Slim Blu-ray
 
Hmm.

The heat and/or airflow issue is bugging me.

I can see the GPU mooching along fine at 40-odd degrees but thats the temperature of the air that then gets blown through the PSU, presumably gaining a fair bit more heat.

I'm considering flipping the psu fan so the slightly warmed air from the psu cools the gpu instead of the fairly hot air from the gpu er... roasting the psu.

A vent will need to be carved into the case side so the hot air can get out again without having to go through to the cpu area.

Anyone thinking this sounds like a cool guide to follow must be off their head, I've voided a stack of warranties and I'm in significant risk of bricking expensive electronics :p
 
Mmkay I've flipped the fan.

The PSU is now running cooler (as it would) but now there's a new issue in my mind that the fan won't ramp up properly now.

Currently the GPU is idling on 55, not over the top but the point is the fan will not respond to the GPU heating up because the sensor controlling it is in the PSU.

So. looks like I may have to feed the wire for the fan inside the psu to the fan header on the card. Should be fine supplying power to the 80mm slim fan since the dual 40mm stock fans apparently pulled more than twice the current.

Modding never stops :eek:



During a run of 3dmark 06 the GPU reached 91 degrees C.

The fan failed to spin up at all because the sensor in the PSU was at no more than 30 degrees.

Needless to say 91 degrees is unacceptably high and I'll definitely have to rearrange how the fan is controlled before using the system for gaming in any way.



In other related news it runs very quietly and scored over 14k in 3DMark06.
 
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