Anyone knows if it will cause any compatibility problems to enable udma using xdma.sys in dos? I started to wonder because speedsys stopped showing hard drive benchmark results after I put it in config.sys.
Yeah you will probably discover glitches with some software, and the practical benefits for DOS are questionable. I bet the forum is packed with talk about DOS drive DMA if you do a search. 😉
wrote:Yeah you will probably discover glitches with some software, and the practical benefits for DOS are questionable. I bet the forum is packed with talk about DOS drive DMA if you do a search. 😉
I did some searches before and I didn't find much. There was only one other thread that even mentioned xdma and that was about sound cards. I have not tested much, but it felt like at least quake started so fast that it felt almost instant with udma turned on.
If you know any threads that talk about what kind of glitches it causes, I would appreciate a links to those threads.
I think I was playing around with that driver earlier this year. I ran into some problems with Carmageddon not loading correctly.
This might be the same or newer driver?
http://optimizr.dyndns.org/dos/drivers.html
If it works for you that's great. Worst that can happen is a hosed filesystem. 😎 When I think about the history of IDE DMA, I believe it wasn't enabled by default until Win2k (excluding UDMA66 because problems). I would say it wasn't until SATA that things really worked well.
As for other threads I'm not sure exactly what to search for but DOS IDE DMA experimentation isn't unheard of.
wrote:I think I was playing around with that driver earlier this year. I ran into some problems with Carmageddon not loading correctly […]
I think I was playing around with that driver earlier this year. I ran into some problems with Carmageddon not loading correctly.
This might be the same or newer driver?
http://optimizr.dyndns.org/dos/drivers.htmlIf it works for you that's great. Worst that can happen is a hosed filesystem. 😎 When I think about the history of IDE DMA, I believe it wasn't enabled by default until Win2k (excluding UDMA66 because problems). I would say it wasn't until SATA that things really worked well.
As for other threads I'm not sure exactly what to search for but DOS IDE DMA experimentation isn't unheard of.
I don't know if that driver has anything to do with xdma. I think xdma is the driver that comes with the Freedos.
I have no idea if xdma is good because I am just now testing this motherboard and I only have phil's benchmark pack on the hard drive. It seemed to improve loading speed of quake and it reduced doom benchmark score by about 100 realtics.
If I knew what others have had trouble with when using udma in dos, I could concentrate on testing those and see if any newer version of the driver has fixed any glitches. That carmageddon might be a good option to try.
I don't know if that driver has anything to do with xdma. I think xdma is the driver that comes with the Freedos.
Jack's drivers used to be included with FreeDOS until him and FD maintainer(s) had a squabble about something. The old one was called UIDE, which I tried briefly on a P3/440BX system. Some benchmarks showed an improvement but it's hard to say how much real-world improvement there would be since DOS software loads pretty fast as it is on a P3. There is no write-behind caching, so that could be a minus compared to plain old SMARTDRV for copying files (at least when the source and destination are the same disk). On some systems where the BIOS defaults to a low transfer speed I guess loading the DMA-enabled driver could make a big difference. But on my P3 disk access is reasonably quick from the beginning.
I wouldn't say that there should be much of performance improvement once you are in game, but loading times were clearly affected.
If I have a slave drive in the same cable, I get performance improvement in doom benchmark, but I get pretty much same performance improvement if I remove the slave drive. In speedsys basically I get 6Mb/s if I have slave drive and 12Mb/s if I remove the slave drive and with udma enabled I don't get any transfer speed results in speedsys. So with doom 12Mb/s is enough to get same performance as if udma was enabled and it doesn't need any faster read speeds.
Quake clearly loads many times faster while udma is enabled, but I suppose the loading time isn't that long without udma that I couldn't wait for it to load.