MiniFrankenMod

System Details

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Notes

Work In Progress: I managed to cram a GTS 450 into a Dell GX790 Small Form Factor machine w/ some mild electronics knowledge and some Dremel cut'n'grind action... ...Yes, I'm a ghetto-broke gamer, and for every reason I know that this is wrong, shouldn't work, you need a 1.21 gigawatt PS to run this card in such a weak setup, blahblahblah... (Before I start - This will void all warranties I'm sure, and results may vary... Don't hold me responsible if you decide to try and embark on this journey and end up letting out all of your magical factory smoke from your system) The Dell Optiplex GX790 Small Form Factor unit comes with a 240w power supply, it's not much to work with, but it is enough to power a single EVGA GTS 450 unit (~105w) with some modding... Obviously the case top had to be cut to accommodate the cards size, but the card itself had to have the plastic shroud removed (no fear though, the small space on either side of the card and the fan up front creates a decent venturi anyways) which involved removing the heat sink from the card and unscrewing the cover from the bottom of the heat sink itself (this was a good time to apply some Arctic Silver 5), and the motherboard/case internals needed some modifications as well (removal of part of the peripheral holder chassis, removal of the holder connector stud from the motherboard, and removal of the two rear slot bays from the back of the case). I also created a custom cable that goes from the 6-pin PCI-E male connector to a SATA male end as the 790 SFF only had 1x SATA plug left open for use (now, you can forego this cable by going with a SATA male to LP4 adapter, then a single to dual LP4 adapter, then to the dual LP4 to 6-pin PCI-E but given the tight area I had to work with, along with airflow and power waste issues I decided to solder up what I needed myself as -nobody- currently makes this cable). In the end, according to my buddies Kill-A-Watt I am currently running @ 238.6 watts w/ the video card overclocked and under full load and I have pretty much maxed out the +12v rail on the PS, so no case lights or extra fans for me, but it is working and perfectly stable. I plan on fabbing up some RAM heatsinks so that I can get the memory clocks up a bit farther, and as soon as I can find a BIOS editor that can properly mod a 450 GTS w/ a GF116 VPU I'll be able to bump up my VGPU a bit higher (started @ 822 Core / 1804 mem @ 1.012 and am currently @ 1098 Core / 2052 Mem @ 1.150v) Not sure where else I can go w/ this setup currently since this Dell mobo is pure, uncut weaksauce; I suppose if a better CPU presents itself I could probably cut some more case and graft in a better PS but for now it plays Skyrim nicely which was all I really needed for the moment. =) Update 01/08/12: Something that was annoying me about this particular card (newer GF116 rev.) was it's inability to overclock the Mem Clock as far as it's GF106 predecessor; my initial theory was that the GF106 model used Samsung K4G10325FE-HC05 chips but the GF116 model uses Hynix H5GQ1H24AFR-T0C chips and I just figured they didn't like to push as far (maybe cheaper or something)... Either way, I figured that I would dig in and figure out a solution to cool things off a bit, hopefully buying me a few extra cycles... As I took a look at things I realized that this was going to be a bit rougher than I had initially imagined as four of the eight chips were covered up by the VGPU heatsink; so I needed to figure out a way to cool them as much as possible without having them actually touch the main sink as the heat being generated on that front would be worse than just leaving them naked... What I eventually came up with was to rip apart an old notebook heatpipe and radiator end and take two of the radiator strips and place them to the RAM chips via double sided heat tape; this still gave me a bit of clearance and also created a small venturi for air to pass over and through each chip keeping things cooler. :) So, I figured while I was at it that I should go ahead and heatsink the Voltage Regulators as well as since I am pushing the voltage from 1.012 to 1.150v that I was probably creating a bit of heat in that area as well... This again proved to be a bit more difficult then it was with the original rev. GTS450 because on that model the VREG's were all in a row so a standard rectangle sink would have covered them easily, but on the newer model they placed a few of the VREG's farther away and also placed a few good zise resistors and a large capacitor in their path, so I had to dremel out a custom sink (not a big deal, but it was another 45 minutes of measuring and cutting)... Once it was all done I slapped it all together and put it through it's paces; overall I am quite impressed with the results... Previous I was only able to clock 1095 Core /1826 Mem, but I am now able to push the MemClk up to 2033 with full stability! Conclusion: I find it hard to believe that the small amount of copper I placed on each chip actually let me push the clock ~210mhz. farther simply on it's own; I almost have to believe that cooling off the VREG's had some hand in this as well... I do notice that when I touch them while at full load that the heatsinks are actually somewhat warm, so I have a feeling that I may have been getting small amounts of ripple previous... Recommendations: Throw some heatsinks on your RAM and VREG's! If you have the room use something better than I did, but even if you don't just keep in mind that anything is better than nothing. :) Fan Mod: The stock/reference fan on most current Nvidia cards is the AVC DASA0815R2U, it's a custom 75x75x15 unit with a 0.60a draw and a max RPM of ~4200... All things considered a very good fan, but for ~$5 at an electronics store you can purchase and mod an AVC DASA0820R2U unit, it's a more common to find/purchase 80x80x20 still with a 0.60a draw and a max RPM of ~4550. So, what I did was cut the new fan out of it's square shroud so that it looked like it's smaller brother, the next problem though was that the screw holes did not match up since the new unit came in a shroud and didn't have any, but not to fear as since both units are AVC the backing plates are the exact same and can be swapped out! Once I realized this I knew that I was home free, so once the fan was mounted back on the heatsink I then cut off the speed control wire on the fan, and although I ran the RPM sensor wire back to it's stock connector I decided to run the voltage wires up and over direct to the +12v connectors at the back of the card on the 6pin PCI-E snap-in as I was tired of the silly 70% max fan speed... Once I did both of these quickie mods, my card runs a bit cooler at idle and can take more abuse before heating up! I do not have the stock plastic ferrings on the outside of my card due to size limitations of my machine but I would imagine that you could shave 5mm circular off of the sides of the fan hole, and so long as you had ~5mm of extra room between the top of the card and your next peripheral you would be just fine!

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