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Video Card Modding
If you visited this page at an early stage, you would have found the comparison of the image quality of my Matrox G400 and my Hercules GeForce 2 GTS card. That page is still available here. However, the original page was designed to support a particular thread in the Overclockers Australia Forums. When other sites started to link to it, the page was often viewed without the right context which led to confusion. Therefore I have decided to give a little bit of background information prior to the actual comparison.
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Roots of Dissatisfaction
When I first built what is now my secondary computer back in 1999 (with a Pentium-II 400 at the time), it came with a Sony 200ES monitor and an S3 PCI video card. I got the S3 card simply because I was waiting for the newly released Matrox G400 which was not yet available. The image quality was absolutely appalling, with the upper left corner being so blurred that you could hardly read the "My Computer" icon on the Windows background.
Later, the monitor moved to what is now my primary machine, with a Hercules Prophet-II video card. That improved the image quality a bit, but compared to the other machine - now with a Matrox G400 on a MAG DJ717 monitor, it sucked in a big way.
Monitor Blues
One part of the problem was obviously the monitor. The MAG DJ717 is a dated design from 1997 or before. It may not be perfect, but it has 0.22mm horizontal dot pitch and an excellent image. The Sony 200ES is obviously an economy model with more limited specs. What I also didn't know at the time, that the highly marketed Trinitron tube is actually not the prime choice for high resolution images (like small text on a computer screen). The advantage of the Trinitron tube is in the area of brilliant colour, which makes it more suitable for television or 3D gaming.
Anyway, apart from the limited specs, my Sony 200ES showed quite a strong convergence fault, particularly in the top left hand corner. A few weeks ago, for some reason, I had enough of it, opened the monitor and found a number of small controls. I don't really know what they are there for, but I tried to wiggle them while checking the effect on the screen. In the end I had found a setting that significantly improved the image. If anybody is going to try the same: be very careful as there are extremely high voltages present in a monitor. Make sure you check the image quality on every part of the screen, since improving one part often worsens another and you have to make a balanced choice.
The S3 video card - Eagle brand
Some time ago I started working on building another low-end machine, based on an i440LX motherboard in AT form factor. I might put a write-up on the web another time. Anyway, I am currently using my old S3 video card in that machine.
I had read about the Nvidia image quality fix on the internet before. And maybe in my unconscious mind I had played with the idea of doing the fix to my Hercules card at some point. However, when I made the decision to use the S3 card for my i440LX project, the idea came up to remove the low pass filters to improve the image quality. If things went wrong, the financial damage would be marginal.
I did the mod a few weeks ago, and I couldn't check the results straight away since I did not have a CPU at the time. It involved removing six SMD capacitors and replacing three ferrite inductors by wire bridges.
Whereas replacing the inductors was a standard soldering exercise, I had some problems with the SMD components and I used this exercise to improve my skills in that respect. It would come in handy later when I modded the GeForce. As you can see, the capacitor C29 lost a soldering pad (luckily it is no longer required), and C22 saw a soldering pad come off the PCB. It is now firmly fixed by solder.
For desoldering the capacitors I have developed the following technique: I check on the PCB and using a voltmeter which side carries the signal and which side is GND. There is no harm in losing the soldering pad on the GND side, whereas the other one might be crucial, depending on the board layout. I then heat the component on the GND side for a number of seconds, swiftly place the soldering iron on the signal side and flick the component off with a controlled amount of force. This way the signal side remains unharmed whereas the GND side may lose part of the pad.
Anyway, I saved the best for the end. When I finally got the CPU a week ago, I started setting up the machine, and I was totally flabbergasted by the crisp image quality - given my previous experience of not being able to read "My Computer" in the upper left corner.
The Nvidia based card - Hercules Prophet II
Having drooled over the S3 video card for a little while, I could not stop myself from pulling the Hercules out of my primary computer there and then. I quickly cross-checked an internet resource for the image quality fix and did it within half an hour. For those interested, a good web site for a description of the fix is http://www.geocities.com/porotuner/imagequality.html.
As you can see, I removed nine capacitors as described above, and I shorted the inductors in each of the three signal lines. That part was actually very easy. I cut 3 wrapping wires to the right length, fixed them with sticky tape so they couldn't move, and soldered them on top of the inductors.
While we are at it, let's have a quick look at another mod I made on this video card soon after I got it. I replaced the minute original heat sink:
The heat sink I bought for a few dollars in Singapore, Sim Lim Tower. It belonged to an AMD K6-2 previously. I sanded it down and attached it with screws from behind, with Arctic Silver II thermal grease in between. Please note that you need to be very careful not to harm the PCB. On this occasion I used self made plastic washers to protect the PCB.
The 50mm fan is designed to run at 12V. Unfortunately it turned out to be the loudest object in my computer. That's why I run it at 7V only. The cooling capability is still far greater than the original heat sink & fan.
Let's now look at the result of the image quality fix. Unfortunately I was prompted to take screen shots only after the modification was made. Therefore I have no pictures of the image quality before the mod. I did take screen shots of my Matrox G400 and my Hercules Prophet II, each time on both my MAG DJ717 and my Sony 200ES monitor.
To give you an idea, here is the direct comparison of the two monitors, both times with the Matrox G400:
Just compare the Gs in "Logged". I think, it is pretty obvious that the MAG (on the left) has a better picture by a long shot. Note that the pictures have been taken close to the centre of the screen, which makes the Sony look better than it is.
Here is a comparison of the two video cards, both times on the MAG monitor:
I suppose they are very close, maybe the Matrox (on the left) looks marginally crisper. But whatever the difference, it is hardly visible at this resolution (1024x768). Given the reputation of Matrox and Nvidia based cards, I think, this is a pretty good achievement for the GeForce 2.
I have prepared a page with frames that allows you to compare the various combinations of video cards and monitors. Just click here.
So much for now. Feel free to send me an e-mail at any time. Thanks,
Martin
Addendum
In case porotuner is down, here is a site that mirrors porotuner and has Filipe's user experience added as well.