Performance
BlueSCSI supports up to Fast SCSI up to UltraSCSI FAST20 (up to 18MB/sec synchronous) with overclock.
💡 Tip:
More details of the FAST20 overclock are here: https://github.com/BlueSCSI/BlueSCSI-v2/wiki/Ultra-SCSI-Fast20-OverClock
When tuning for performance there are a few factors to keep in mind:
- The rating, brand, and wear of your SD card can significantly impact performance.
- The SCSI drivers (especially on a Mac) can make a huge difference. FWB has the best performance on Power Macs, but is not universal so is not included on pre made images.
- If an image file is fragmented on the SD card performance will be much slower. You will see a warning in the log file.
Results
If you are adding your own result to this page you MUST include the SD Card brand/rating and testing tool. Ones that don’t will be removed.
| Machine | Drivers | SD | Tool | Read | Write | Notes | OverClock | Pico 1 or 2 |
|---|---|---|---|---|---|---|---|---|
| PowerMac 9600 | FWB | SanDisk Extreme 32GB A1 | FWB Bench | 8.6 MB/s | 7.3 MB/s | On internal Fast Bus | N | Pico1 |
| Beige G3 | FWB | WD Purple 32GB UHS-1 | SCSI Dir 4 | 3.3 MB/s | 2.9 MB/s | Internal Narrow Bus | N | Pico1 |
| Beige G3 | 8.1.4 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 9.5 MB/s | 6.1 MB/s | Adaptec AVA-2906 PCI | N | Pico1 |
| LC 475 | 7.3.5 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 4.84 MB/s | 4.48 MB/s | Internal | N | Pico1 |
| Performa 575 | 7.3.5 | Samsung Pro Endurance 256GB U3 | SCSI Dir 4 | 5.1 MB/s | 3.6MB/s | 5MB Bus, DB25 | N | Pico1 |
| II | 7.3.5 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 1.63 MB/s | 1.38 MB/s | Internal | N | Pico1 |
| IIci + cache card | 7.3.5 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 2.09 MB/s | 2.03 MB/s | Internal | N | Pico1 |
| IIvx | 7.3.5 | Samsung EVO Plus 256 GB | SCSI Dir 4 | 1.57 MB/s | 1.40 MB/s | Internal | N | Pico1 |
| Quadra 700 | 7.3.5 | SanDisk Extreme 32GB A1 | SCSI Dir 4 | 4.3 MB/s | 4 MB/s | 5MB Bus, DB25 | N | Pico1 |
| PowerBook 180 | Mac OS 8 (driver only, not OS) | WD Purple 32GB UHS-1 | SCSI Dir 4 | 1.9 MB/s | 1.5 MB/s | Internal Narrow Bus | N | Pico1 |
| PowerBook 180 | Mac OS 7.5.3 | WD Purple 32GB UHS-1 | SCSI Dir 4 | 0.7 MB/s | 0.8 MB/s | Internal Narrow Bus | N | Pico1 |
| PowerBook 170 | Mac OS 7.5.3 | Gigastone Gaming plus 32GB A1 | FWB Bench | 1.7 MB/s | 1.4 MB/s | DB25 | N | Pico1 |
| 1 PowerBook 140/170 | Mac OS 8 (driver only, not OS) | WD Purple 32GB UHS-1 | SCSI Dir 4 | 1.65 MB/s | 1.5 MB/s | Internal Narrow Bus | N | Pico1 |
| 1 PowerBook 140/170 | Mac OS 7.5.3 | WD Purple 32GB UHS-1 | SCSI Dir 4 | 0.65 MB/s | 0.73 MB/s | Internal Narrow Bus | N | Pico1 |
| Plus | 7.3.5 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 0.45 MB/s | 0.25 MB/s | SCSI Accelerator 7.0 extension | N | Pico1 |
| SE | 7.3.5 | Sandisk Extreme Pro 64 GB UHS-3 | SCSI Dir 4 | 0.68 MB/s | 0.50 MB/s | External port, desktop version in a case | N | Pico1 |
| SE/30 | 7.3.5 | Samsung Pro Endurance 32 GB | SCSI Dir 4 | 1.79 MB/s | 1.48 MB/s | Internal | N | Pico1 |
| Classic | Mac OS 7.1.1 | Kioxia 32GB Exceria U1 | SCSI Dir 4 | 0.68 MB/s | 0.59 MB/s | Internal Bus - exFat | N | Pico1 |
| Classic II | 7.3.5 | Samsung Pro Endurance 32 GB | SCSI Dir 4 | 1.35 MB/s | 1.10 MB/s | Internal | N | Pico1 |
| SGI O2 | IRIX | WD Purple U1 | diskperf | 9.52 MB/s | 6.89 MB/s | External SCSI-2 | N | Pico1 |
| NeXTstation | NeXT | PNY Elite-X U3 | Drive Performance | 2.29 MB/s | 1.11 MB/s | Internal 50-pin (bus limited to 5MB) | N | Pico1 |
| PS/2 8556 | FAT16B | Sandisk Extreme Pro 64 GB UHS-3 | Norton System Info 6.0 | 2.8 MB/s | - | Internal (5Mb/s) | N | Pico1 |
| HP B132L | exFAT | Samsung Pro Endurance 128 GB | hdparm | 8.57MB/s | - | External 50-pin (synchronous 10MB/s) ,Linux | N | Pico1 |
1 This PowerBook is badged 140 on the display but SCSI Director reports it as a 170.
Seek
Note that seek numbers are meaningless in a SD solution - they wait 10ns (10ms on SCSI-1 bus) then return good as there is no actual head to move.
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