Overclockers.com—Busmastering!

After a bit of research on busmastering, I found out the following:

First, you must have Windows correctly recognizing the PIIX3 or PIIX4 chipsets before any busmastering software is installed. According to Intel, neither W95 or W98 does this, so you have to install a patch: 95setupex.exe or 98setupex.exe. These patches do not install busmastering, but add data to an INF file so that the chipsets are recognized by Windows.

Second, depending on what version of Windows you have, you should install either the Intel Drivers or Microsoft.

If you have W95 retail or OSR1, you can use the Intel or Microsoft drivers. However, the patch used in step 1 may not work on the OSR1 version of Windows; Intel flatly states that “OSR1 is not supported with the Windows 95 INF Update Utility”. In this instance, you may get a yellow “!” in Device Manager for your IDE Controller. If this happens, it looks like you can’t install busmastering, or at least a stable version. If you don’t have the “!”, you can use either the Intel Drivers or the Microsoft Drivers using Remideup.Exe from Microsoft’s download site.

If you have OSR2 up to W98, Intel states that you “should NOT use the Intel Bus Master IDE Driver.” Instead, use the Microsoft Drivers included with each version. I think the reason for this is that the Intel Drivers are “mini-port” drivers which do not support many ATAPI devices, like CD ROM changers, tape drives, ATAPI Zip Drives and IDE drives >8.4 gig. Microsoft’s Drivers are full port drivers which support all these devices. I doubt if Intel is going to spend much time on enhancing their drivers as they advocate using the Microsoft Drivers instead.

All of this presupposes that the OS is clean and there are no conflicts. In addition, there can be no real mode drivers in Config or Autoexec. If you have the Intel drivers installed without updating the INF file, you have to uninstall the drivers and start with updating the INF file. If you use the Intel Drivers, you can’t have the ATAPI devices listed above. You must also check that you don’t have “NOIDE” in your Windows registry; if you do, you have to edit it out.

Check out these references for detailed information:

Download 95- or 98setupex.exe and read the README carefully.
Article ID # Q154435 in Microsoft’s patches download.

http://www.microsoft.com/hwdev/devdes/idedma.htm

http://www.storagereview.com/articles/9803/980311busmaster.asp

http://www.intel.com/design.motherbd/ideinfup.htm

If you have non-Intel chipsets, you’re in a different world.

"Out, Out Damned Heat!"

Or, you could try a “Power Supply Fanwich”. You could mount a second fan on top of the power supply fan, although this is difficult to do with an ATX PS. But you could add a second fan either inside the PS or directly outside on the PS vents, thereby boosting its exhaust. This can be a noisy approach and one I have not fully explored, but I thought I’d mention it anyway.

So, 60 cfm in, 60 cfm out.

Next, vacuum the case out!

General Rule 9: The more metal shavings left in the case, the higher the repair bill.

Now you put the guts back in, power up the machine and start feeling around for hot spots. Off the bat there are two areas, drives and video cards. There are a number of products geared to solving local hot spots by moving hot air out into the exhaust flow. So the objective here is to move stagnant hot air pockets into the chimney to be exhausted.

General Rule 10: Fans inside the case move air within the case.

Each case will have its own unique problems in this area. As a rule of thumb, look at the cards in your case. If they look like a pyramid (ie longest cards in top slots) you’re creating a big hot pocket. Arrange cards so that the longest are on the bottom, the shortest on the top. Look at your drive cables; these big fat obstructions should be moved OUT of the air flow. Obstructions such as these will materially affect your case temp.

Now I have not covered the CPU because I’m assuming you have taken care of that – there are a host of articles on CPU cooling and products available, and I assume you’ve covered this base effectively. But –

General Rule 11: The cooler the CPU, the cooler the case.

A Final Thought:

There’s nothing like a good hardware store for finding the little odds and ends that make projects like these fun.

PS: So what’s in my case? I have a 120 mm front fan 51 cfm at 29 dBa, metal cut away to improve airflow, a Radio Shack 9cfm blower aimed at my SL2W8 running at 450, an AAVID PII chip cooler, and the Power Supply fan. My case does not get more than 10 degrees over ambient. I’m still experimenting with noise control and now find that the power supply fan is the loudest. I will be trying to sound isloate the power supply and probably change this fan for one that’s thermally controlled.