Impact
Site Admin Joined: 01 May 2004 Posts: 3258 Location: Pinecrest, FL	Posted: Thu May 06, 2004 11:32 am    Post subject: Mod :: Dual Power Supplies   For a while now I have been having problems with my computer when running games (or anything demanding) and benchmarks. The problem was: after running something strenuous for a short bit of time, either the graphics would freeze up, or the computer would restart itself. When I say "freeze up", I mean the graphics would stop refreshing, and sound would continue as it should, but I wouldn't be able to do anything due to a lack of refreshing graphics. Naturally, I instantly blamed windows, and reformatted. Then when the problem persisted, I was forced to look for other, more hidden reasons. As most computer enthusiasts know, whenever something starts going wrong, its most likely: Window's Fault Malfunctioning Hardware A problem with newly added hardware I had recently added two new items to my computer, both of which I thought could be the culprit. The first: A 256mb PC3200 stick of ram from Crucial which I had added about two weeks ago. The second: An ATI Radeon 9800 Pro which I had added a week ago. Now, for those of you not too familiar with finding a problem in a computer, there are things to look for. The problem I was having was related to graphics not refreshing, or my computer restarting when using lots of power. When there is a problem with ram, its normally characterized by "Blue Screens", when windows loses track of files you need, or windows claiming it cant find a file it just had a second ago. The graphics card seemed like a much more likely answer, first off, it has to do with graphics, and second, it uses a LOT of power. For those of you who don't keep up with the new graphics cards, the newer ATI and nVidia cards both need an extra power supply (4-pin molex). The next wave of cards (to be released over the summer) requires two. Now, having seen problems like this before, it seemed that the graphics card wasn't getting enough power, and dying (no refreshing), or tripping the power protection circuit on my PSU (power supply unit) and the PSU was turning itself off to avoid damaging itself or other components. This led me to an all new question: Was my PSU not strong enough for my system? I found it hard to believe that my system was drawing too much power out of my Antec SL350 (350w). The Antec SL350 is a beast, though wattage ratings generally mean very little, Antec is an extremely good brand when it comes to power supplies. I talked with some friends, and asked them if they thought it could be too weak of a supply for what I was running: Gigabyte GA-7VAXP Motherboard AthlonXP 2100 (2) 80gb Western Digital 7200rpm 8mb Cache HD's 52x CDRW Radeon 9800 Pro Sound Blaster Live 5.1 Koolance Water Cooling System (PC2-601 Black) (3) 80mm Case Fans (2) Small Water Pumps LCD Display/Control board (3) 80mm Quad-LED Case Fans Ultra Violet Cold Cathode After a day and a half of talking with other modders and friends, the conclusion was quite clear: The SL350 should be able to run it, but perhaps the Koolance system was drawing a bit too much from it. The only way to find out: test it. This brought me two possible testing solutions, buy a new power supply, if it didn't help, return it. Or the more entertaining option: add a second power supply to my system. By the title of the article, you should know which option I picked. Once fully decided on the idea that I would add a second PSU to my computer, I (very enthusiastically) grabbed my roommates old computer, and proceeded to pull its crappy little 200w PSU out. My roommates old computer (PSU half out) Once out, the PSU needed to be cleaned, which was easily done by removing the top cover, and blowing compressed air through it to remove dust. The next major step in my "mod" was to find a nice place to put the extra PSU. Obviously outside of the case wasn't really an option, because that would require a side panel off, and that would severely hurt air flow. The two places I was eyeing were the only places large enough for a PSU to fit, the 5.25" drive bays, and the very bottom of my case (under the 3.5" drive bays). One of these was easily ruled out by the fact that the extra PSU's wires weren't long enough to reach the full height of the case (and the Koolance power connector is in the top-most back corner of the case). The spot I decided on: the 3 open 5.25" bays in my case. After quite a bit of "wiggling" (yes, the technical term), and a slight bit of help from a screwdriver, the second PSU fit in the drive bays almost perfectly (its in there well enough that it wont move, even without screws), but I could get it out again if I needed to. It takes up two 5.25" bays (almost exactly). The power supply inside the case. Front of the case with 2 of the 3 drive bays covered. Front of the case with 2 of the 3 drive bays covered and the power cord connected to the PSU. Front completely covered, and the power cord coming out the side (the front bezel even closes). Side view of both power supplies inside. The 2nd powersupply is not sheathed yet, but it should be soon. In the upper left, you can see the control board for the Koolance that the new PSU is connected to. The next major thing I did was determining what to run on each power supply. This wasn't very difficult, and if you are following along, doing this yourself, the answer is: hardware components go on the good PSU, extra stuff goes on the second PSU. The reason for this is simple, it is easy to "short" a power supply, and have it running all of the time; it's harder to relay the power supplies so that one "trips" the other, and they are both on at the same time and off at the same time. I decided on having my Koolance system (whole cooling system), my case fans, and my cold cathode on the 200w PSU. This way, my cooling system is always running, along with the fans and light. The computer can turn on and off, but these still run. The SL350 is left running the Motherboard, CPU, Graphics Card, Hard Drives, CDRW and Sound Card (a load it can easily bear). I was somewhat worried though, trusting the heat dissipation of my computer to a generic 200w power supply didn't see like a good idea, but I was reassured when I remembered MBM (Motherboard Monitor). Motherboard monitor gives you the option of setting off an alarm when your computer temperature reaches a certain level, or the option of having the computer shut itself off. I set the temperatures in MBM for an alarm at 45c, and automatic shutdown at 50c. With water-cooling, I am rarely above 33c, and either of those temps would mean an obvious problem someplace. This way, if my extra PSU dies out, and the cooling stops working, my computer will shut itself off before any damage occurs. Now for the last piece of the project, shorting out the extra PSU so that it will be on anytime the switch is on (this model didn't have a switch, so it's on anytime it is plugged in). I had a jumper wire in a drawer, so I used that, but friends have told me, the true way to do it is with a un-bent paperclip. All you need is some sort of conductor going from the green wire on the motherboard power connector to any of the black (ground) wires. A picture is shown below, sorry about the fuzzyness, my camera does not like focusing close up. The green wire is the fourth from the left (if holding the connector with the clip side up), and a ground wire is two to the right of the green. So, connect the fourth and sixth wires from the left on the clip side (see pics). Shorting the power supply motherboard connector. Another picture of how to short the PSU. Well, after all that work (actually, only about 20 minutes, and 10 of them were spent finding a power cord), I got my computer back up and running. I noticed a difference RIGHT away. Before adding the second power supply, I had had problems in BIOS, any time the screen would change refresh rates, or resolutions, my monitor would go black, and I would need to turn the monitor off/on to get it to come back up (this happened multiple times on each boot). With the second PSU added, this problem went away. And now, I can benchmark, and run games without the problem of my computer restarting due to lack of power. Turns out the Koolance PC2-601 does suck quite a lot of power. If you have one, and are noticing problems with crashing, you might want to look into adding another PSU, or buying a new one. Good Luck and Happy Modding!
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