First post, by Half-Saint
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landmark, checkit, norton sysinfo
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wrote:wrote:landmark, checkit, norton sysinfo
Thank you. I was able to confirm that my XT is running at full 8 MHz.
I ran a hard drive test on a 64MB CF card and transfer speed came out at 486 KB/s. Is that normal for this class of machine?
Yes. If you never had prior experience with XTs they do seem too slow. But that's what they are.
wrote:wrote:Yes. If you never had prior experience with XTs they do seem too slow. But that's what they are.
This is actually my parent's old PC and I used it as a kid. I just don't remember it being so slow 🤣
Maybe a 16 MHz 286 would be better as it will run at 8 MHz with turbo off but then it wouldn't be an XT anymore 😀
You could swop out the 8088 CPU with an NEC V20. At the same clock speed, you should still see a slight performance boost.
Found a video of an XT machine (-NEC V20 @8MHz-) running CheckIt..!
About 133KB/s were the transfer rate of an old 11MB drive, so it's not that bad, actually.
https://www.youtube.com/watch?v=RKVx8Fssmbc
Some versions of DOS also run faster than others, I remember.
MS-DOS 2.x's boot code could be loaded from within a single sector (or track/cluster ?), so was much faster than DOS 4/5/6.
Another issue is DOS 5/6 being slow in displaying DIR command on XT class machines (equipped with 8088, at least).
Maybe loading fastopen helps a bit. Or using another DOS. Compaq DOS, FreeDOS (16-Bit), DR-DOS, PTSDOS, PC-MOS/386 ..
Alternatively, it's also possible to use a CF card with an internal cache.
It would at least decrease access time a bit, I think. Speaking of access time, some CF cards behave totally different.
Some are as fast as 1ms, some as slow as 12ms, even. I used to use HDTune with an USB 3.x card reader on Windows to benchmark them.
Another issue is the sector alignment. Unlike NFTS or EXT2/3. FAT12/16/32 never has the same alignment.
On writing, this almost always causes a read-modify-write, which can cut performance by half.
That's one of the reasons why Windows98 can be dog slow on a modern SSD (unlike a real RAM Disk). 😉
Edit:
wrote:You could swop out the 8088 CPU with an NEC V20. At the same clock speed, you should still see a slight performance boost.
I second that! The original 808x was very primitive in its design, lots of microcode to circumvent a "flawed" design. 😉
It lacked physical support to do address calculations (such as base+index), for example. A feature that was so fundamentally required by the x86 architecture.
The 80286 and the NEC V20/V30 (?) were much more thought through in that respect, I think.
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel
//My video channel//
I started with 286/16 and this is/was my base line. One time I used an XT for an hour or so... I was glad I had a 286 🤣 That's also why I don't have any desire of having pre-286 PC stuff. It's just too slow...
Requests are also possible... /msg kixs
wrote:I started with 286/16 and this is/was my base line. One time I used an XT for an hour or so... I was glad I had a 286 🤣 That's also why I don't have any desire of having pre-286 PC stuff. It's just too slow...
Yeah, another limiting factor is that 360K floppy although I'm currently fine with using the CF card to transfer software. Most old stuff works fine but yeah, it is slow... it holds quite a lot of nostalgia value for me but it would help, if it was just a bit faster. Maybe I'll invest in a 286 turbo card some time in the future...