Here’s a central location for the disk data transfer rates I have personally measured using CBM Disk Transfer Benchmark. I’ll include a table of results for both load and save transfer rates and bar graphs below those.
Unless otherwise noted, testing was done on a real NTSC Commodore 64 with stock KERNAL and a 1541 disk drive. Disk Transfer Benchmark measures the time it takes for the call to the LOAD or SAVE routine (via KERNAL vector) to return, using the CIA’s real-time clock. For more details, see the DTB info page.
These tables are obviously not exhaustive, as there are many more cartridges, KERNAL replacements, disk drive models, and software IRQ loaders, etc., than what I have tested here. However, these scores were all made using the same testing methodology and personally done by me.
LOADING
The baseline DTB Load Score of 1x is the average time it takes to load a 177 block file with a vanilla Commodore 64 and 1541 Disk Drive.
| System | Load Bytes per Second | Load Time | DTB Load Score |
| 1541 | 403 | 01:51.5 | 1x |
| SD2IEC | 502 | 01:29.5 | 1x |
| 1581 | 507 | 01:28.6 | 1x |
| 1541 w/ KCS Power | 1303 | 00:34.5 | 3x |
| 1541 w/ Better Working TURBO | 2101 | 00:21.4 | 5x |
| 1541 w/ Epyx Fastload | 2121 | 00:21.2 | 5x |
| 1541 w/ Mach 5 | 2121 | 00:21.2 | 5x |
| 1541 w/ Warp Speed | 3017 | 00:14.9 | 8x |
| 1541 w/ Final Cartridge III | 3406 | 00:13.2 | 9x |
| 1541-II w/ JiffyDOS | 3746 | 00:12.0 | 9x |
| 1541 w/ Super Snapshot 5 | 4163 | 00:10.8 | 10x |
| 1541 w/ Action Replay 5 | 5352 | 00:08.4 | 13x |
| 1541 w/ Retro Replay PAL 3.8q | 5352 | 00:08.4 | 13x |
| 1581 w/ JiffyDOS | 6515 | 00:06.9 | 16x |
| SD2IEC w/ Epyx Fastload | 7136 | 00:06.3 | 18x |
| SD2IEC w/ JiffyDOS | 9175 | 00:04.9 | 23x |
| 1541 w/ DolphinDOS (U64)* | 9366 | 00:04.8 | 23x |
| 1541 w/ Transwarp 0.84 | 16056 | 00:02.8 | 40x |
| 1541 U2+ Hyperspeed (USB) | 64223 | 00:00.7 | 161x |
| 1541 U2+ Hyperspeed (RAM Disk) | 89912 | 00:00.5 | 225x |
| U64 Hyperspeed (USB) | 224780 | 00:00.2 | 562x |
| U64 Hyperspeed (RAM Disk) | 449560 | 00:00.1 | 1124x |
Loading Comparison Graphs
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- Load Bytes per Second comparison, EXCLUDING U64 Hyperspeed.
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- Load Bytes per Second comparison, including U64 Hyperspeed.
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- Baseline 1541 load rate compared to CARTRIDGE-BASED fast loaders.
*Notes
- Transwarp speeds were measured after using cc1541 to create encoded files, including the data binary stream DTB loads.
- U64 Hyperspeed was measured on the 1541 Ultimate-II+ connected to an NTSC C64, and also on a Ultimate 64 Elite. In both cases, speeds were measured for attached USB storage and also the internal RAM disk.
- Retro Replay was tested on a PAL Commodore 64, because the NTSC version failed the tests on my computers.
- SD2IEC scores were tested with an SD2IEC from TFW8b.
- DolphinDOS was tested using an Ultimate 64 Elite, not real hardware.
SAVING
The baseline DTB Save Score of 1x is the average time it takes to save a 177 block file with a vanilla Commodore 64 and 1541 Disk Drive.
| System | Save Bytes per Second | Save Time | DTB Save Score |
| 1541 w/ Epyx Fastload | 342 | 02:11.5 | 1x |
| 1541 | 370 | 02:01.5 | 1x |
| 1541 w/ Mach 5 | 371 | 02:01.3 | 1x |
| 1541 w/ KCS Power | 371 | 02:01.2 | 1x |
| 1541 w/ Better Working TURBO | 371 | 02:01.1 | 1x |
| 1581 | 749 | 01:00.0 | 1x |
| SD2IEC w/ Epyx Fastload | 870 | 00:51.7 | 2x |
| SD2IEC | 871 | 00:51.6 | 2x |
| 1541-II w/ JiffyDOS | 925 | 00:48.6 | 3x |
| 1541 w/ Super Snapshot 5 | 1170 | 00:25.4 | 5x |
| 1581 w/ JiffyDOS | 1905 | 00:23.6 | 5x |
| 1541 w/ Final Cartridge III | 2007 | 00:22.4 | 5x |
| 1541 w/ Action Replay 5 | 2443 | 00:18.4 | 7x |
| 1541 w/ Retro Replay PAL 3.8q | 2470 | 00:18.2 | 7x |
| SD2IEC w/ JiffyDOS | 2775 | 00:16.2 | 8x |
| 1541 w/ Warp Speed | 2900 | 00:15.5 | 8x |
| 1541 U2+ Hyperspeed (USB) | 3978 | 00:11.3 | 11x |
| 1541 U2+ Hyperspeed (RAM Disk) | 4683 | 00:09.6 | 13x |
| 1541 w/ DolphinDOS (U64) | 5352 | 00:08.4 | 15x |
| U64 Hyperspeed (USB) | 9565 | 00:04.7 | 26x |
| U64 Hyperspeed (RAM Disk) | 37463 | 00:01.2 | 102x |
| 1541 w/ Transwarp 0.84 | FAIL | FAIL | FAIL |
Saving Comparison Graphs
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- Save Bytes per Second, EXCLUDING U64 Hyperspeed
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- Save Bytes per Second, including U64 Hyperspeed
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- Baseline 1541 save rate, compared to cartridge-based speed loaders.
*Notes
- Transwarp failed the save benchmark because the drive entered an error state after jumping to the SAVE routine.
- U64 Hyperspeed was measured on the 1541 Ultimate-II+ connected to an NTSC C64, and also on a Ultimate 64 Elite. In both cases, speeds were measured for attached USB storage and also the internal RAM disk.
- Retro Replay was tested on a PAL Commodore 64, because the NTSC version failed the tests on my computers.
- SD2IEC scores were tested with an SD2IEC from TFW8b.
- DolphinDOS was tested using an Ultimate 64 Elite, not real hardware.