Water cooling, SLI graphics cards, and lots of air in said water cooling

Discussion in 'Hardware' started by Mimsy, Jun 22, 2008.

  1. Mimsy

    Mimsy Superior Imperial Queen of the MG Games Forum

    I think my computer has a cooling problem, or more accurately, a heat problem. It has shown tendencies to freeze up during games (the very purpose of this system and the reason it was purchased), especially graphics intensive ones.

    Since The Guy and I have been busy buying a house and moving to it, I didn't have time to look into the issue until this weekend. I apologize in advance for the long post... I'm trying to make sure I don't over-look anything.

    This weekend, partially unpacked and reasonably settled in the new house. I started started checking temperatures with SpeedFan. My goal was, of course, to try and determine if it was heat that caused the freeze-up crashes.

    When running a game, or when running Folding, the CPU gets up to around 90C and steadily climbing, after 10-15 minutes. One of the two 8800 GT cards--the lower one, sits steady at around 65, and the one in the top slot actually has not been checked by SpeedFan, since it was removed before I started, on grounds that it's on-board heat sink was hot enough to literally burn my fingers. So I don't have an actual number for that card's temperature, but I am quite sure that hot enough to cause visible burns on human skin is a bad thing in a graphics card.

    Here's where it gets interesting. My dual-core CPU is water-cooled, and the tubes pass right above the burning hot 8800GT, with less than half an inch to spare. When I touched the tubes, they were both very warm to the touch, and though I know practically nothing about water-cooling, I do realize that one of the tubes is supposed to carry cool water to the CPU, so if both of them are very warm, then the pump is trying to cool the CPU with warm water.

    The reason I originally removed the top graphics card was a vague notion that if extreme heat is radiating from the videocard and heating up the water tubes, that may over time damage the CPU. Heat is bad for electronics. As I had the computer on its side, working on removing the card, I noticed that one of the watercooling tubes looked empty. After reassuring myself that nothing had leaked onto the motherboard I finished what I was doing, set the system right side up again, and started it, to get fresh SpeedFan readings. it took the water cooling pump nearly a minute to work the air away and get water going, and as I type this, with the case side off, I can see lots of little air bubbles go through the tubes.

    My first question is: Should the large amount of air in the tubes concern me?

    My second: If that is a bad thing, how do I fix it? Can I fix it, or should I take advantage of the fact that the entire system, including workmanship (I paid to have it built) is still under warranty?

    Third question: If the air is normal, should I assume that topping off the water cooling is regular maintenance once or twice a year from now on, much like the water in the car battery?

    Fourth question: If the over-heating video card is the cause of my problems, is it a safe assumption that replacing it will solve the heating issues, or should I look into repositioning those water tubes?

    I apologize again for the very long post, especially since I am sure I have left out a lot of important information. I'll be happy to provide more, just let me know what you need.

    Oh, one more thing: The case is a CoolerMaster Cosmos. Two fans on top, one on bottom, mesh front and back, and I keep the computer on my desk, so airflow should not be a problem. The fans could be spinning faster, however, I am reluctant to mess with that until I have unpacked far enough to find the motherboard manual.

    Thanks in advance for all help! :wave

    EDIT:
    In case it matters, with the side off and the burning 8800GT removed, the CPU cores are steady in the lower 60's. Celsius, and with Folding running on both.
     
  2. Speculant

    Speculant The Confused One

    i dont really have much experience in water cooling, but after some searching on google, i found that bubbles are bad.

    FROM THIS ARTICLE: http://www.overclock.net/overclock.php?file=articles/water-cooling-guide.htm

    Filling, Bleeding, and Leak Testing Your System

    Explanation of bleeding: You have to get the water into your system some how, right? When you first put the system together air is in your lines. To get the water into the system I like to use a T-line. The only purpose of this line is to give you a place to pour everything in and let air out. If you’re using an anti-corrosive, you have two option for mixing your coolant:

    Option 1 (easier!): Get a gallon of distilled/de-ionized water, pour it into a larger container, then add 6.4 ounces of anti-corrosive (or 4oz if that is all you have), close container tightly, shake (not stir :p) container. And there is your coolant. Mark on the container “TOXIC! DON’T DRINK! BAD! TOXIC!” Or something like that. You now have enough coolant to fill 3-5 watercooling systems!

    Option 2: As you fill your system with water, measure or estimate the amount of water you are pouring into your system, then find 5% of that. That is how much anti-corrosive to add. You don’t want to have your system 98% filled then try and get 5% of anti-corrosive in. It’s not going to happen. So you have to pour water in, get some air out of your lines (to allow for more fluid), pour 5% of anti corrosive in, then pour some more water in, then pour some more anti-corrosive in, and so on. I would prefer having less than 5% of anti-corrosive, opposed to more than 5%. The first way is easier yes? But I will use the second method since it is more complex (needs more explaining).

    1) Once everything is together, it’s time to fill the lines with coolant! Get a funnel, put it in your fill/bleed line, and pour some of your distilled/de-ionized water in. If you plan on using an anti-corrosive additive, it’s a good idea to keep track of about how much water you have used. That way you know about how much anti-corrosive to add. Once the water level is about 4 inches from the top of your bleed line, stop pouring in water.

    2) Now carefully tilt your case back and forth (make sure you don’t splash water out of your T-line). As you tilt the case, you will see air pockets moving around. Tilt the case so that the air pockets make it to the T-line and float out of the system. Your water level will have dropped due to the amount of air being removed from your system. Now if you want to use an anti-corrosive, find the amount of water you have poured in so far, take 5% or that, and that is the amount of additive to add at this point. If you’re using spa sanitizer to keep any biological growths from appearing in your system later on, pour some into the cap of the bottle, and just pour about a teaspoon in (Sanitizer is not good for you! Don’t measure it out with any cooking tools, just guess on the amount. Don’t even touch the stuff). NOTE: Some spa sanitizer doesn’t react well with anti-corrosive. It turns it into a gel... kinda. Just use as little of each as possible.

    3) Now pour in enough water to get your water level back to about 5 inches below the top of the T-line. Then tilt your case back and forth some more to get more air out. While doing this, keep an eye on your tubing to see if there are any pockets of air left (there could be unseen air in your heater core/waterblock). If you see pockets of air, get most of them out.

    4) Once the water level gets below your T-fitting, you have to pour in more water. Also add about 5% of anti corrosive, if you're using any. Then look around for air pockets one more time. If you see major ones, try and get them to float out. Then top off your T-line off with water yet again.

    5) Now double check that there are no obvious leaks. There shouldn’t be unless you messed up big. Now plug the T-line with something just to make sure water doesn’t spit out of it when you start your pump. Before you start your pump there will be small air pockets left in your lines. Starting the pump will turn the air pockets into tiny bubbles. Plug-in and/or power up your pump with-out the computer on. Now unplug your T-line.

    6) As the water and bubbles cycle through the system, the bubbles will pass through the T-line, and some of the bubbles will float up the T-line, and out. It will take a few hours for most of the bubbles to be removed, but that’s ok, you have to leak test your system for at least 24 hours! Just keep an eye on the coolant level and keep adding water as needed. The level of coolant in your lines might drop as much as 2 inches the first half hour (depending on how much air was left in the system). If the water level drops any more than that, check carefully for leaks (which you should be doing anyways). Your waterblock, fittings, and joints are all possible spots for leaks. But if you have everything clamped down correctly and added your fittings to the heater core correctly, you should be fine. You can put a paper towel or two down at the bottom of your case and below any fittings. This will help you be able to spot any water that has dripped from a leak.

    7) Once it’s been 24 hours and you have no leaks, you are free to fire up your system. Make sure the pump is running as well as the fan on your heater core. Go into your BIOS and keep an eye on your CPU temperature for the first minute just to make sure the waterblock is mounted correctly. At a stock CPU speed, your CPU temperature should be around 35C-42C full load (room temperature will affect your temps quite a bit). After that you’re free to start overclocking/using your bad mahmuh-jahmuh system!
     
  3. Mimsy

    Mimsy Superior Imperial Queen of the MG Games Forum

    Wow. That is an impressively long reply. Thanks :)

    I'm serious. I'll come back for this for future reference. I've been emailing the company I bought the computer from, while posting here, and if they are willing to let me send the whole thing in for full repair, I will do that before trying to repair it on my own.

    Once more, thanks for the long and detailed reply. I'm sure it will be very helpful down the road :)
     
  4. Speculant

    Speculant The Confused One

    you're welcome:) I'm glad I could help.
     
    Last edited: Jun 25, 2008
  5. Mimsy

    Mimsy Superior Imperial Queen of the MG Games Forum

    Good news! CyberPower's reply email said, in summation: "here's an RMA number, send it back to us and we'll fix it"

    I have emailed them back and asked about turn-around times and who pays for the shipping, and if I need to send the hard drive with the rest of the system (can't do fresh back-up as over-heating shuts down computer during). I will make my decision based on what they say.
     
  6. Mimsy

    Mimsy Superior Imperial Queen of the MG Games Forum

    UPDATE: CyberPower said I can hang on to the hard drive if I have sensitive data on it, and turn-around is 3-4 weeks, including the time to ship the computer both ways. I pay for shipping it to them, they pay for shipping it back. I am now investigating what that will cost me.

    And the hard drive will stay here. Honeymoon photos qualify as "sensitive data".
     

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