Little diferent hard disk benchmark

ParanoidLittleMan · August 7, 2018

Usually transfer speed is what is measured in case of hard disks/Flash card adapters, and sometimes access time - what is little more complicated case, but certainly is much better with Flash cards, since no mechanic - in range of 1mS by faster solutions - on Atari STs .

I will now give some real work test results with different settings, different filled partitions, different driver/TOS, with very simple test. All is made on same computer - Mega STE, with same UltraSatan, with 2 SD cards with practically same speed.
Test is just copying SUBDIR with 80 very short files to some other SUBDIR on partition.

For DOS/TOS compatibles of 500 MB minimum buffer size is 32 KB, what hard disk driver must create.
TOS 2.06, TOS/DOS compatible partition of 500 MB, filled 80% :
At 8 MHz: 58 sec , at 16 MHz 40 sec

Almost empty 500 MB partition:
At 8 MHz: 39 sec , at 16 MHz 27 sec

TOS 1.04, 8 MHz for same as above: 38 sec - marginally faster.

Improved TOS 1.04 (without large sectors), DOS FAT16 partition of 1000 MB, 80% filled:
No added buffers, only base 2 KB, what TOS creates.
At 8 MHz: 67 sec , at 16 MHz: 46 sec
With 32 KB added buffers:
8 - 66 sec, 16 - 46 sec

Improved TOS 1.04 (without large sectors), DOS FAT16 partition of 1000 MB, almost empty:
No added buffers, only base 2 KB, what TOS creates.
At 8 MHz: 26 sec , at 16 MHz: 17 sec
With 32 KB added buffers:
8 - 25 sec, 16 - 17 sec - marginal improvement, or just in range of test error.

So, what affect most speed during copy of short files ? It is how much partition is filled. The reason is how TOS FAT16 filesystem work: it needs to search by every write through FAT, from start for empty clusters, and when finds, it will copy there. That search takes much more time when partition is filled, of course.
Could make if faster with really large buffers, like over 300 KB . That may be for some of next tests. Smaller cache, like 32 KB here helps almost nothing.
Then, CPU speed is very important - even if disk transfer and access speed is same, there is lot of it to do for CPU during file access and copy.

Improved TOS is faster too - see 26 secs vs. 39 secs for copy on almost empty partition (8 MHz) , The reason is that no large sectors, so it will transfer only 1 sector instead 16 (that's minimal block size (8 KB) in case of 500 MB TOS partition) in case of short files (or short file chunks) access .

Edited August 7, 2018 by ParanoidLittleMan

ParanoidLittleMan · August 8, 2018

If someone want to make this test on his config, here are files:

80.zip

Depack it on your Atari disk, media , Then create some new SUBDIR, or use existing one, different from source SUBDIR, and copy there DIR 80 . Start clock after copy dialog appears, in same moment when clicking OK or press ENTER. Stop when copy is finished. With Satandisk it will be for sure much slower.

May give your config parameters: which Atari machine, TOS v. , used mass storage adapter, card type, used hard disk driver SW and how much cache it installed - later is not so easy to check, usually need to go in installing SW. In case of my PP TOS/DOS drivers it is 32 KB .

This test may look trivial for some, and yes, it is. But who wants, can really learn some things about how all it works, and what is worth to care about.