I've had to restore my (Norton Ghost) image each time with the earlier versions of the Win2K ATA100 drivers. HD Tach gives horrible CPU utililization scores running WinME with the Intel ATA drivers, but I think (not sure) this is due to a problem with HD Tach, more than the Intel drivers. The guy who writes the code for HD Tach admitted that he needs to update the program, but hasn't had time. See here for what Intel has to say about HD Tach. 

Both WinME & W2K will run fine (maybe better) without the the Intel ATA100 drivers. No single hard drive can yet saturate an ATA66 bus. The fastest drives can barely sustain 40MB/s at the fastest parts of the disk (outer sectors). The IBM 75GXP (one of the fastest ATA drives) claims to sustain a maximum data x-fer rates of 37MB/s. See here for an HD Tach benchmark of an IBM Deskstar 75GXP hard drive. 

update 15jul2001: Running ATA33 and ATA100/66 devices on the same cable. Intel addresses this in Guide4.pdf, which is posted here ( ftp://download.intel.com/support/chipsets/ultraata/ - Intel might have blocked access from this page, so you might have to copy-n-paste the URL into another page. Or better yet, use an FTP client). If you click on the heading labeled Independent Configuration of Different Devices on the same Cable (item 9.6), you'll read this <copy-npaste>:

The Intel Ultra ATA Driver allows different IDE or ATAPI devices that have different maximum transfer rates to be independently configured, even when both devices are located on the same IDE cable.

For example, if you have an IDE hard drive that is capable of Ultra ATA/66 transfers set up as the Master device on the Primary Channel and you have an ATAPI CD-ROM that is only capable of UDMA-2 (Ultra ATA/33) set up as the Slave device on the Primary Channel, each device can be independently configured.

In the past, the slowest device installed on an IDE cable determined the rate at which both devices could transfer data. In the above example, this would mean that the rate for both devices would have been set at UDMA-2 because it is the slowest device. This was done to ensure that a device using an older technology was not damaged by using a transfer protocol that it was incapable of using. 

The Intel Ultra ATA Driver allows each device installed on the same IDE cable to be independent of the other device.

</paste> I bolded parts of the text for emphasis.

update 15jul2001: There are problems with the CPU utilization part of HD Tach. Intel discusses these problems here.

update 10mar2001: I installed that Intel 6.10 drivers last night, to both WinME & W2K (created images first). They seem to work fine for me, except HD Tach doesn't seem to like them. It locks on me in Win2K. Haven't tried WinME. Again, I tend to think this is more of a problem with HD Tach. Intel lists known issues & solutions here. 

update 05mar2001: Haven't noticed any probs myself, but received a note from Ken Hilts, who says: To add to your CUSL2 notes, I've had two problems with the latest Intel ATA drivers (v610 beta2):

1.) My CD burner (Plextor 12/10/32 ATAPI) is the master on my secondary IDE channel. If it has a disk in the tray at boot, I get the BIOS message Secondary Master Fails. This doesn't occur with Microsoft drivers, or any earlier Intel drivers. The problem is reproducible and "moves" with the Intel v610b2's. 

2.) A couple of games (Unreal Tournament, Deus Ex [based on UT engine?]) won't start cuz they don't 'see' the game CD, even tho it's been inserted, and plenty of time is allowed for spin-up. Again, reproducible and not present with other drivers. [Thanks, Ken]

* Microsoft says W2K has no ATA100 sppt. See here. MS introduced ATA100 support to W2K with Service Pack 2.

* Warning: When running the HD Tach bench, do not put a check in the box labeled Enable write test. At least one person has over-written portions of their data. If you read the instructions that comes with HD Tach (who reads instructions?), you'll see that the Write test is (only) for drives with a single partition, and it will overwrite your data. 

I tried to perform the Write test, but HD Tach wouldn't let me, saying that I had multiple partitions on the drive (which I do). This is another reason why it's always good to have a back-up image of your boot partition on hand - so you can painlessly restore, within minutes, anytime you have a problem.

* One guy at asusboards.com forum posted benchmarks with various versions of Intel ATA drivers. Some benches looked better with the old, original drivers, but he had no ATA100 drives (only ATA33 & ATA66). All Intel ATA drivers are (supposedly) backwards compatible. 

 So it would be only slightly limited by running at ATA33 speeds. No probs running either ATA66 or ATA100 drives at ATA66 speeds (interface). At the end, I drop links to some benchmarks I've run on both HD Tach & Sandra. 

* Microsoft details how to enable ATA66 x-fer protocol for Win2K here (W2K comes with native ATA66 sppt). The Intel chipset drivers you install to Win2K (also) come with ATA66 drivers, but not ATA100 sppt. If you don't do the little registry tweak here, you'll be running at ATA33 protocol. Be extra alert anytime you bust into the registry. I had no prob - worked like magic.

* update 09mar2001: Microsoft has a W2K fix for ATA100. W2K does not natively sppt ATA100. This fix will supposedly be part of SP2, and MS suggests you wait for SP2, cuz the version of this fix that comes with SP2 will/may receive additional testing. I have downloaded the patch, but not installed it. You can read about & grab the patch here. 

* update 16may2001: Microsoft posted Service Pack 2 for Win2K. It has ATA100 support. Many people are using SP2 with no problems. You can download SP2 (for Win2K) here. 

* My understanding is that both IDE/ATA controllers are ATA100-capable, but you need to use an 80-conductor ATA cable in order to get ATA100 performance from your (ATA100) drives. Seems that Asus ships only one 80-conductor (ATA100/66) cable with the board (the one with the blue connector). So if you want to use ATA100 drives on both ATA channels (at ATA100 protocol), then you'll need to buy another 80-conductor (ATA100) cable, which I've done. You can order/buy ATA100 cables (up to 36 inches) here. 

* Asus color-codes the Primary IDE/ATA channel with a blue connector - same color as the connector on the ATA100 cable. This should not be interpreted to mean that only the Primary channel supports the ATA100 protocol. It means they only intended you to run ATA100 drives on the Primary channel. Most people run CDROMs or CD burners on the secondary channel, which don't require an 80-conductors ATA66/100 cable. But people like me, who have SCSI CDROMs and burners, use the secondary channel for ATA100 hard drives. 

* The second IDE/ATA cable that Asus ships with the CUSL2 is not an 80-pin (ATA100) cable. 

* If you have an ATA100 drive and you use an 80-pin (ATA100) cable, your drive's DMA Setting should (automatically) be set to [5]. If it doesn't, this might indicate a problem, such as, the drive is not really ATA100-capable, or the cable is not 80-conductor.  

* Many (most?) prefer Microsoft ATA66 drivers drivers that comes with their OS'es (W98/SE, WME, W2K), citing lower CPU utilization & better performance. Seems that Microsoft rocks at writing drivers. They perform comprehensive testing before releasing drivers. Once Microsoft gets their hands on the Intel ATA100 driver, I'm sure they will make it work without problems. 

* You usually have to go into the drive's settings in the Device Manager in Win98/SE/ME, and put a check in the DMA box, in order to enable DMA transfers, which yield a substantial performance improvement & lower CPU utilization. This is something you definitely want to do. The OS may give you a caution/warning, but if you know your hard drives are DMA capable (all hard drives manufactured in last couple years are DMA capable), then you definitely want to do that. You will need to reboot before the settings take effect.

* Some people are having problems getting ATA33 hard drives running in DMA mode in W2K. In the BIOS, they can't set the drive to anything except for Auto, or DMA [2]. They also get horrible HD Tach scores from the drive under PIO mode. They have no such trouble in WinME or W98/SE.

* After installing the Intel ATA100 drivers, the DMA check box disappeared from the device manager. Some say that ATA drives will show up as SCSI devices in the Device Manager after installing the Intel ATA100 drivers, and that this was normal.

Latest Intel drivers here. 

* Traded a few emails with Greg Smith, who makes HD Tach. He says HD Tach supports both WinME + Win2K, but they're "seeing a lot of issues with the Intel driver and various software/hardware. The worst issues are with the W2K version of the driver."

Adrian has written to tutorial on how to enable/ensure DMA transfers in Win2K here.

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