Graphics card air flow + Screws for GPU Problems! (Please read!)

I am guessing based on your pictures that you have a brand name box. Probably a Dell ?

In any case, they don't always use normal screw holes. Those sticking out pins where the screw holes are serve to hold the card in place sometimes and an additional clip then goes over this to secure the card (Dell and Lenovo does that a lot).

As for your air space, be sure to remove all the rear PCI brackets to allow air to flow outwards above the GPU space. If you have a front case fan in this section (Dells usually do) that pushes air in, opening those rear brackets will complete the flow to allow hot air exhausted by the GPU's cooler to be circulated to the back and out.

Having said all that, in your case, the air flow isn't that high (brand name box, again), so I would recommend a reference styled, squirrel-cage cooler that directly exhausts to the outside. Those coolers on GPUs cope a lot better with reduced room and air flow situations. I have a similar brand named box that I used a few different GPUs with, and while you can get away with open-air coolers, those direct-exhaust to the back, squirrel-cage coolers typically do the best.

I also noticed that your card you linked to is a DDR3 version of the HD7750. Go for a GDDR5 version!! DDR3 HD7750 is a reduced-price model of the much faster HD7750 with GDDR5 (full-fledged model). GDDR5 has twice the bandwidth of DDR3 at the same speed, so go figure.

The ASUS HD7750 is also a nice card and runs cool. The HD7790s are really nice too, get one on sale, and it'll be around 100 bucks.

All those fans like the Evercool one you linked to, exhaust air to the outside. Check your case to see if you have some spots to install additional fans, especially on the front. With HP, there usually isn't much, just a spot or 2 on the back side for exhaust fans.

Can you check to see if your PSU includes a 6 PIN GPU power wire harness ? If it does, you can safely toss in a HD7790 or so. What is the wattage of your PSU ?

The air space itself seems rather OKAY. There is enough room for any (up to 2 slots wide) GPU and any cooling configuration of the GPU (open, closed, semi-open/closed), BUT you absolutely need some air flow. To get that air flow, open up the brackets above the GPU, then either install some fans front or back. If there is already a back fan installed, you can use a set of wire-cutters to cut off the steel mesh that usually blocks a large amount of air flow to get more air flow. This sets up the system to take in some air over the GPU via the open slots, then exhausted by the rear fan (or air flows over the GPU then out the slots, for front-fan configs).

I am guessing based on your pictures that you have a brand name box. Probably a Dell ?

In any case, they don't always use normal screw holes. Those sticking out pins where the screw holes are serve to hold the card in place sometimes and an additional clip then goes over this to secure the card (Dell and Lenovo does that a lot).

As for your air space, be sure to remove all the rear PCI brackets to allow air to flow outwards above the GPU space. If you have a front case fan in this section (Dells usually do) that pushes air in, opening those rear brackets will complete the flow to allow hot air exhausted by the GPU's cooler to be circulated to the back and out.

Having said all that, in your case, the air flow isn't that high (brand name box, again), so I would recommend a reference styled, squirrel-cage cooler that directly exhausts to the outside. Those coolers on GPUs cope a lot better with reduced room and air flow situations. I have a similar brand named box that I used a few different GPUs with, and while you can get away with open-air coolers, those direct-exhaust to the back, squirrel-cage coolers typically do the best.

The raised edges on the PCI-bracket (those little clips) will be digging into the screw hole spot on the GPU mount side. Then some kind of a clamping mechanism holds the whole thing together. Study the case carefully and you should see what I mean.

In your case, if you don't want to upgrade the PSU, then I would only recommend the HD7750, GDDR5 edition. It is a really good card, and better than what you have now by far.

Okay, you can still improve the cooling situation without money. Here are a few ideas:

1) Put the computer on the ground (ideally in the basement if you have a workstation desk there). Air is cooler closer to the bottom of the room.

2) Check the computer for dust (CPU, intake holes, exhaust holes, and even in the PSU, blow it out with some compressed air, if you have some, or just vacuum it, CAREFULLY, out of the meshes) and cable mess. Tidy up the cables (carefully) with zip-ties or those steel-in-plastic garbate bag ties. Move them out of the way of air flow (do your best on this).

3) Cut that mesh at the fan. You'll be surprised how much air it withholds. Typically up to 40% (meshes are rated for % perforation, which can be equated to % air flow allowed), so if you cut it, 100% of the air pushed by the fan will be exhausted, improving airflow.

4) Check in the BIOS settings of the computer to see if there is a fan control speed setting. Usually it is along the lines of "quiet, normal, max, etc.." boosting this will change the response of the fan to thermal conditions (ramp up quicker or more aggressively).

Those are the most important aspects.

Well, I'm glad you are doing okay with your GPU. Be aware though, for GPUs, more VRAM isn't always better. You need the render back-ends (ROPS) to actually make good use of all that VRAM and you need the VRAM bandwidth (both width and speed) to actually fill that VRAM in the time required. The HD7750 doesn't really need more than 1GB of VRAM, because it only has so much render back-ends and is clocked rather low. By the time you actually need more than 1GB of VRAM to store whatever, the GPU has ran out of steam in a desperate attempt to fill that much VRAM. DDR3 is also half as fast as GDDR5 at the same clock. The GDDR5 versions of the HD7750 has the VRAM clocked at least 4.5 Ghz (effective clock), your DDR3 version is clocked at 1.6 Ghz for the VRAM, so the bandwidth on the GDDR5 version is at least 2.8 times more. In other words, the DDR3 edition is nearly 1/3rd the memory bandwidth of the full speed version. All that really means is that at low resolutions and settings, the two cards will be roughly the same, but at higher resolutions (1080p, for example) and higher settings (especially AA), the DDR3 version will be a LOT slower. This is just a FYI, since you have already bought the card. I don't think there is a better value than spending another 10-15 dollars to get nearly 3 times the memory bandwidth...

As for your case choices, those are all really really big cases. I don't know if you are aware of that already. Most of the people I know who have used the HAF, for example, are walking away from it, because it is just ridiculously big. Just as well, I'm not sure your case is a standard ATX from the pictures you took. The motherboard is mounted (what looks like in your pics) on the opposite side of the case, with the expansion slots at the middle of the case. That looks like BTX. I don't know if your mobo will physically install into an ATX case (only a very few BTX boards do, once you flip them, without problems, that is).

And about your PSU, anything Seasonic is a top notch choice, at a price, of course. If you prefer Corsair, nearly everything Corsair these days is a good choice. The cheaper CX series will do just fine, and you can usually snatch up a good CX500 for really cheap (like 30 dollars or so) when they go on sale at various places. Avoid CoolerMaster. Antec is not as high in quality (in parts, capacitors for example) as Corsair for the same money.

Yeah, your case definitely looks like a BTX design. You can check to see if your BTX will actually fit in an ATX case, some earlier BTX boards are actually able to fit into ATX cases if you just flipped them.

BTX never took off in the DIY market, so large manufacturers never produced consumer grade BTX boards, and thus, no cases either. If you have a BTX, you are pretty much stuck with the case you have, and if you want more cooling, you can mod the case to its full potential. That's about it. There isn't much aftermarket (actually, nearly none) for BTX specific stuff.

You can toss in a more powerful PSU. The PSU looks to be a standard ATX PSU by its mounting holes and dimensions.

Either way, why not save up some money until you build a new computer ? Then you can choose all the parts you want, and won't have to be stuck with some obscure standard.

Congrats! Probably the simplest thing to do on a brand name box to improve air flow these days...

For your parts, I think the best idea is to snatch up heavily discounted items when possible over the next few months. The end of the year usually comes with heavy discounts to move inventory. What I usually do is to wait for sales, and buy an item I will use fairly soon. I managed to buy a 3570K for 159.99 a long while back, and an Intel 520 240GB SSD for 169.99, an Intel 330 240GB SSD for 139.99, two awesome DangerDen acrylic cases for about 20 bucks each (going out of business sale), and so on. Doing things this way, a piece at a time when they are on sale really saves you a lot of money. You also need the flexibility to buy whenever the sale goes on (so hold on to your money for a short bit), and don't be too exact with a model number (i.e., if a Corsair PSU that is 500 W goes on sale, and you wanted a 450 W mdoel, don't hesitate).

Have you also tried www.ncix.com and www.tigerdirect.com, and even Amazon has amazing deals once in a while.