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OS/2 - ArcaOS 64Bits Kernel Discussion
Lars:
--- Quote from: Dave Yeo on December 12, 2020, 08:47:23 pm ---Is it just me, but I find the ramdisk to be pretty slow, barely faster then my USB2 disk. Disk 4 is the Ramdisk and disk 5 is the USB3 on USB2 HD.
--- Code: ---Hard disk 4: 255 sides, 1138 cylinders, 63 sectors per track = 8926 MB
Drive cache/bus transfer rate: 26649 k/sec
Data transfer rate on cylinder 0 : 23463 k/sec
Data transfer rate on cylinder 1136: 20314 k/sec
CPU usage by full speed disk transfers: 11%
Average data access time: Disk read error.
Multithreaded disk I/O (4 threads): 22193 k/sec, 12% CPU usage
Hard disk 5: 255 sides, 60085 cylinders, 255 sectors per track = 1907728 MB
Drive cache/bus transfer rate: 25500 k/sec
Data transfer rate on cylinder 0 : 21492 k/sec
Data transfer rate on cylinder 60083: 21287 k/sec
CPU usage by full speed disk transfers: 1%
Average data access time: 20.4 ms
Multithreaded disk I/O (4 threads): 21347 k/sec, 2% CPU usage
--- End code ---
I had the impression that the PAE disk interface is actually implemented as a char device rather then a block device.
--- End quote ---
Architecturally, an ADD driver qualifies as a char device because it has a driver name. But of course, it works with blocks of 512 byte sectors, just like any other ADD. ADDs introduced a special entry point into the driver to improve performance and simplify interface between DMDs and ADDs.
Andi B.:
Doug wrote -
--- Quote ---but FAT32 is always slow, even in windows (and it has other limits,
--- End quote ---
Doug you wrote that numerous times but IMO you're wrong.
Copy paste of my measurements I posted somewhere else about USB3 speed -
--- Code: ---Win7 to NTFS - 113 MByte/s
Win7 to FAT32 - similar
eCS, usb11.17 to JFS - 18 MByte/s
ArcaOS, usb12.07 to JFS - 17.5 MByte/s
( ArcaOS, usb12.07 to FAT32 - 0.13 Mbyte/s )
--- End code ---
This figures are for writing a single large file to an external hard disk. These clearly show that for other OSes usually the speed of the external hard disk is the limiting factor. Not the filesystem (nor USB). At least with large files.
Only with OS/2 - ArcaOS we are limited by the drivers. And additionally, our FAT32 is exceptionally slow. These are problems of our drivers/OS and our FAT32 implementation. It does not help anyone when you repeat again and again that this may be a filesystem problem. So please stay on facts. Thanks.
Lars:
--- Quote from: Andi B. on December 13, 2020, 11:48:46 am ---Doug wrote -
--- Quote ---but FAT32 is always slow, even in windows (and it has other limits,
--- End quote ---
Doug you wrote that numerous times but IMO you're wrong.
Copy paste of my measurements I posted somewhere else about USB3 speed -
--- Code: ---Win7 to NTFS - 113 MByte/s
Win7 to FAT32 - similar
eCS, usb11.17 to JFS - 18 MByte/s
ArcaOS, usb12.07 to JFS - 17.5 MByte/s
( ArcaOS, usb12.07 to FAT32 - 0.13 Mbyte/s )
--- End code ---
This figures are for writing a single large file to an external hard disk. These clearly show that for other OSes usually the speed of the external hard disk is the limiting factor. Not the filesystem (nor USB). At least with large files.
Only with OS/2 - ArcaOS we are limited by the drivers. And additionally, our FAT32 is exceptionally slow. These are problems of our drivers/OS and our FAT32 implementation. It does not help anyone when you repeat again and again that this may be a filesystem problem. So please stay on facts. Thanks.
--- End quote ---
This is remarkable, given the fact that one reason for the new line of 12.xx 32-bit device drivers was increase in performance. Surely does not look like it.
By the way: what measurement tool are you using ? I'd like to crosscheck with my own driver set.
Andi B.:
--- Quote ---By the way: what measurement tool are you using ? I'd like to crosscheck with my own driver set.
--- End quote ---
I usually take LarsenCommander on both OSes as it does the measurement automatically. LCMD also seems to wait until the cache is really written to the disk at the end of the copy process which is especially important on Win. Figures vary slightly when repeating tests a few times. But difference is usually no more than a few percent. To proof my results I also compared with standard copy command and stop watch. I measured from hitting enter until copy and eject finished. Taking into account the additional time eject took all my tests confirmed my initial numbers taken by simply copy from LarsenCommander are good enough to compare OSes/filesystems/drivers.
Cause I thought there is something wrong with my system when running ArcaOS I started the thread on the testers group. Unfortunately it seems ArcaOS and the drivers works as designed and there's no hope that it will get faster in future. At least not for my Intel based system. Maybe with other chip sets. But until now no one come up with better test results.
Btw. I made such tests in the past with your drivers too. They are a bit faster. But the difference is small. Using a different port (different internal chip) does make a lot of more difference. I remember my tests probably > 10 years ago where I could write to a external JFS hard disk with about 22MByte/s (USB2) while Win with the same hardware at that time did about 26MByte/s.
Dave Yeo:
Here I used https://hobbes.nmsu.edu/download/pub/os2/util/benchmark/diskio118z.zip to benchmark my drives. It's old and could use a couple of updates, measurement of my fastest drives bus speed is negative so a variable needs to be bigger and it considers too fast of a seek time like the ram disk or SSD to be a disk error but it measures reading track 0 and the last track directly.
There is also a NT binary in the package.
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