| 1: Intro & spec | 2: First impressions | 3: Installing an HDD | 4: User interface | 5: Timings & performance | 6: Compared to | 7: Conclusion |
CompactDrive PD70X portable storage device review
5: Timings and performance
Note: All Tests performed using a Toshiba 120Gb MK1234GAX. Hard disk reliability is paramount for storing your images, particularly if you're only carrying one device. I use two, the PD70X with a 120Gb Toshiba HDD, and the PD70X with a Western Digital 100Gb HDD to minimize the risk of failure.
Often the prudent option is to buy drives which have been on the market for at least six months; as failure rates become known by that point. Unfortunately that also means you'll be buying older technology, which means slightly slower and slightly smaller capacities. You can check user submitted data for specific drive models on storagereview.com.
Autonomy test results
The key performance feature of any portable storage solution has to be how much data it can transfer between charges. There are three factors at play here, battery capacity, transfer speed, and low power consumption.
In this test the CompactDrive PD70X managed to copy and verify 31Gb on one charge, which is moderately impressive. Unfortunately it ran out of power towards the end of the next card. The good news is that it failed gracefully, displaying an "Err 20" low battery warning; so no data corruption occurred.
Test specs: 2100mAh Uniross Hybrio NiMH, full verify, card: Sandisk Ultra II 4Gb,
PD70X fitted with Toshiba MK1234GAX, ambient temp 20°C
Note: 2100mAh Hybrio batteries were used as they are a low self-discharge type; the capacity is currently typical for this type of NiMH. There are higher capacity NiMH batteries on the market, but many have unacceptably high self discharge rates which limits their use whilst travelling.
Card to HD transfer rates
From the table below we can see the average transfer rate from the card to HDD is 9Mb/s copy only. A reasonably good result for the Sandisk Ultra II used in testing.
For comparison purposes, I also ran a copy using a 2Gb Sandisk Extreme IV. Unfortunately the faster card appeared to be fractionally slower, that said 0.1Mb/s isn't significant:
Test specs: PD70X fitted with Toshiba MK1234GAX, ambient temp 20°C
Small files vs large files
This test is to see whether the copy speed is significantly affected by the number of files, and/or filesizes used. This should give a good indication whether the device can handle the relatively small JPEG files often produced by compact cameras, or whether it's only suitable for large RAW files. The PD70X shows a fair variance here, with small files significantly impacting performance.
Test specs: Sandisk 256Mb Ultra II,
PD70X fitted with Toshiba MK1234GAX, ambient temp 20°C
Computer transfer rates
Obviously high speed transfers from memory card to the PD70X are the most important aspect, but how does it perform when the time comes to copy the data on the hard disk back to the computer? Testing showed below average transfer rates:
Test specs: OS, Windows Vista Ultimate. Hardware, 3.6GHz P4, 1Gb
DDR3200. AVG anti-virus, Windows Defender and Spybot S&D.
USB2 full-speed connnection. Data, 40.3Gb image files (the large RAW files
from the autonomy test).
The torture test
How does the device cope when the unexpected happens? As mentioned above when the batteries are too flat, the device shuts down cleanly. But what happens when the memory card is suddenly removed during a transfer? Again, good news, the PD70X stops with an error message. Turning it off and then back on will clear the error, and you can then copy the whole card again.
5: Timings and performance
Note: All Tests performed using a Toshiba 120Gb MK1234GAX. Hard disk reliability is paramount for storing your images, particularly if you're only carrying one device. I use two, the PD70X with a 120Gb Toshiba HDD, and the PD70X with a Western Digital 100Gb HDD to minimize the risk of failure.
Often the prudent option is to buy drives which have been on the market for at least six months; as failure rates become known by that point. Unfortunately that also means you'll be buying older technology, which means slightly slower and slightly smaller capacities. You can check user submitted data for specific drive models on storagereview.com.
Autonomy test results
The key performance feature of any portable storage solution has to be how much data it can transfer between charges. There are three factors at play here, battery capacity, transfer speed, and low power consumption.
In this test the CompactDrive PD70X managed to copy and verify 31Gb on one charge, which is moderately impressive. Unfortunately it ran out of power towards the end of the next card. The good news is that it failed gracefully, displaying an "Err 20" low battery warning; so no data corruption occurred.
| Test # | Time, inc full verify | Data transferred | # Files | Notes |
| 1 | 24m20s | 3.77Gb |
335 |
Freshly charged NiMH, charged with PD70X |
| 2 | 24m15s | 3.77Gb | 335 | |
| 3 | 24m19s | 3.77Gb | 335 | |
| 4 | 24m17s | 3.77Gb | 335 | |
| 5 | 24m18s | 3.78Gb | 335 | |
| 6 | 24m22s | 3.79Gb | 336 | |
| 7 | 24m20s | 3.79Gb | 336 | |
| 8 | 24m23s | 3.79Gb | 335 | Two out of three bars showing on the battery meter |
| 9 | n/a | n/a | n/a | Insufficient power to complete |
Note: 2100mAh Hybrio batteries were used as they are a low self-discharge type; the capacity is currently typical for this type of NiMH. There are higher capacity NiMH batteries on the market, but many have unacceptably high self discharge rates which limits their use whilst travelling.
Card to HD transfer rates
From the table below we can see the average transfer rate from the card to HDD is 9Mb/s copy only. A reasonably good result for the Sandisk Ultra II used in testing.
For comparison purposes, I also ran a copy using a 2Gb Sandisk Extreme IV. Unfortunately the faster card appeared to be fractionally slower, that said 0.1Mb/s isn't significant:
| Time, copy only | Speed | Details |
| 1m54s | 9.1Mb/s | 2Gb Extreme IV CF, 188 Large RAW files, 1036Mb total |
| 7m11s | 9.2Mb/s | 4Gb Ultra II CF, 345 Large RAW files, 3.88Gb total |
Small files vs large files
This test is to see whether the copy speed is significantly affected by the number of files, and/or filesizes used. This should give a good indication whether the device can handle the relatively small JPEG files often produced by compact cameras, or whether it's only suitable for large RAW files. The PD70X shows a fair variance here, with small files significantly impacting performance.
| Time, inc full verify | File details |
| 2m34s | 1338 small JPEG files, 238Mb total |
| 1m38s | 21 large RAW files, 233Mb total |
Computer transfer rates
Obviously high speed transfers from memory card to the PD70X are the most important aspect, but how does it perform when the time comes to copy the data on the hard disk back to the computer? Testing showed below average transfer rates:
| Read | 8.2Mb/s |
| Write | 7Mb/s |
The torture test
How does the device cope when the unexpected happens? As mentioned above when the batteries are too flat, the device shuts down cleanly. But what happens when the memory card is suddenly removed during a transfer? Again, good news, the PD70X stops with an error message. Turning it off and then back on will clear the error, and you can then copy the whole card again.
This review contains the opinions of the author, which are subjective. All technical data is believed accurate at time of publication, however please check it with the manufacturer before making a purchasing decision. I hope you enjoy my site, and if there's anything you feel could be improved, please drop me a line at: 
All images/text/content © Adrian J Warren 2007.
All images/text/content © Adrian J Warren 2007.