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|9th August 2012, 7:46 PM||#1|
Join Date: Feb 2002
HD7850 OC Question and General New Build Advice
Good evening my technically superior comrades,
I Recently upgraded (pretty much built a new system) for the first time in a little over years. Have gone from:
CPU: Intel E8400 (Thermaltake Big Typhoon that I got eight years ago)
MB: Gigabyte EP35C-DS3R
GPU: Nvidia 9800GTX
Memory: 2x4GB Patriot Signature 1333Mhz DDR3
Case: Antec Sonata II
PSU: Antec Earthwatts 550W (using in new build for now)
SSD: Intel 520 120GB (Keeping of course)
Bunch of optical drives.
CPU: Intel i5-3570k with Corsair H100 (ordered, hasn't arrived yet, using the Thermaltake Big Typhoon in the mean time).
MB: Asrock z77 Extreme4
GPU: Gigabyte Radeon HD7850
Memory: G.Skill Ares 2x8GB 1600Mhz DDR3
Case: Corsair Obsidian 650D
PSU: Antec Earthwatts 550W
SSD: Intel 520 120GB
HDD: One internal magnetic drive.
I know the ram is overkill, but I needed to keep my existing ram in the old system, so that I have a complete system to use or sell (once get either a new PSU for the new system, or get a cheap one for the old system - any recommendations here?). Surely, although the Antec 550w is decent, the new system warrants something a bit more powerful (and modular!). I will be adding a second HD7850 in a month or two.
On to the OC issue... I'm playing around with overclocking the HD7850. After some reading up on the issue surrounding going higher than 1050Mhz (in short, AMD have gone to some lengths in recent Catalyst versions to restrict these cards to 1050Mhz overclocks) I have been able to get it stable at 1100Mhz OC @ 1.225v (the highest voltage any of the OC tools will allow and any lower in volts and it goes unstable).
Whilst this isn't a bad OC overclock (970Mhz stock, and I think around 850Mhz for regular HD7850 cards?), many others have reported much higher clock speeds at lower voltage. The card is running remarkably cool for an overclocked GPU, it seems to stay around 75C with the fan set to auto under the load of MSI's Kombustor GPU burn-in test and in the high 60s if i set the fans to max), which is frustrating, as the heat isn't what's holding it back (these Gigabyte cards have two large fans). Any suggestions would be much appreciated.
Regarding the new build, I have the H100 arriving tomorrow or Monday and am looking to get the best possible airflow going inside the case.
I have also ordered one of these in order to be able to remove all the hdd enclosures from around the front fan. Whether they're in this config or this config I feel that airflow is being interrupted, especially in terms of getting air to the GPU. The advantage of getting that HDD enclosure for the 5.25" Bay is it comes with a 120mm fan, adding a much needed second front intake, hopefully allowing the air coming from the bottom fan to flow towards the GPU (pressure should be lower out of the line of the 120mm fan).
I'm thinking my starting point will be this setup:
Mods: image is on my own hosting.
Have only got the one magnetic drive in the new system and no internal optical drive (planning to keep it that way), I'm using external USB enclosures with the the others hdds for now, along with a slimline USB powered DVD burner (using optical discs less and less, I couldn't believe has fast windows installed on this new system off a USB stick) hot swap bay on top of the case also helps. I am going to get a basic, entry level NAS later this year and then I won't have any magnetic HDDs in the case and will probably get creative with the ssd mount like this guy, but perhaps along the bottom - there is plenty of room for two or three there, just needs to drill a few small holes to mount. This would free up the 5.25" bays for better airflow from the fan, or mount a radiator for future gpu cooling (or a proper customer WC setup).
There seems to be just as many people recommending push, as there is pull for the H100 Rad, as well as exhaust vs intake, so will take the scientific approach and experiment for the best solution temp wise.
I have ordered some BitFenix Spectre Pro fans for the H100, so I could feasibly use the fans it comes with to run a push-pull also. To do this, I would need to run the H100 fan's on the outside of the case to make it fit (don't mind doing this, those LED-less fans would look ok up there.. I intend to try out the various options for fan orientations - this shows the various options, keeping in mind I will also have a fan in the top right corner. To be able to use the H100 as an intake, I purchased one of these - does anyone know if it's feasible to screw the fan screws thought this filer without the small holes turning into large ones? And if so, will the fans have any trouble being that close to the mesh?
Any advice on the HD7850 overclock or the best way to set up the fans when the H100 arrives would be much appreciated.
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Last edited by zztopless; 9th August 2012 at 11:30 PM.
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|10th August 2012, 9:21 AM||#2|
Join Date: Mar 2002
Location: Brisbane, Southside.
The push/pull argument on radiators has been going on as long as there have been radiators. If you are pushing the hot air out of your case thru the rad, it will be slightly warmer. Slightly. Might be only a degree or two, but warmer nonetheless. This could make the difference on your overclocks. Pulling cooler outside air in thru the rad will exhaust the warm air inside your case, making the inside warmer, but with good airflow thru the case from other fans, it should be ok, but it will still cause other components to be warmer. With the H100, outside mounting is almost impossible, but you can mount 4 120mm fans on the H100, 2 on each side, and have a push pull config. That seems to improve performance, but can (depending on the choice of fans) increase noise levels. For H100 advice, your best bet is to go trawling through the thread on the corsair coolers in the WC subforum.
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