Test conclusion
More often large amounts of data has to be transferred, benefits from the extra pace of the SanDisk Extreme Pro USB4, but then has to be ready to spend about twice as much as for a conventional model with USB3.
Per
- Extremely fast data transmission
- A lot of reading/writing access per sec.
Contra
- Very high price
- Long access time when writing
If a new standard for connection sockets is presented, it usually takes a long time before it prevails across the board. USB4 was announced in 2019, but only since the past two years have been increasingly coming with desktop computers and laptops with this technology. Devices for connecting are still rare. With external SSDs there are just 26 models between 1 and 8 terabytes (TB) from five manufacturers (at the test time). For comparison: For models with USB3, the price comparison portal Idealo.de lists almost 900 models. The first USB4 SSD in Computer Bild test laboratory is the SanDisk Extreme Pro USB4 in the 2-TB variant.
Faster is bigger
Current external SSDs are mostly real minis – they quickly disappear in the palm of your hand and usually weigh about 40 grams. The extreme Pro USB4 is significantly larger and heavier. At a fleeting look you could almost think of an external hard drive if it would not be much thinner. Most of your 182 grams is in a solid aluminum housing. This makes it easier to distribute the heat that arises in the company. The extreme Pro gets warm in the operation, but not particularly hot and can be packed again shortly after the set. They are currently available in two memory sizes: as tested with 2 TB for around 320 euros and for 520 euros with 4 TB (prices at the test time). This is around 60 percent more expensive than the sister model Extreme Pro with USB 3.2 Gen 2×2 and more than twice as expensive as competitors with the simpler technology USB 3.2 Gen 2.
What does USB4 bring?
USB3.2 Gen2: This technology can be used to transmit up to 10 gigabits per second (GBPS). This enables maximum data rates of 1.1 gigabytes per second.
USB3.2 Gen2x2 doubles the pace to 20 Gbps. This enables data rates of up to 2 gigabytes per second. However, Gen 2×2 is quite rare. Some manufacturers like Apple do without it.
USB4 Increases the pace to 40 Gbps. This means that up to 4 gigabytes per second are in data transmission.
The SanDisk Extreme Pro USB4 is much faster than older external SSDs with USB3.
Photo: computer picture
Sometimes the SSD hesitates
The new SanDisk reached many records during the pace measurements in the test: when reading 3,804 megabytes per second (MByte/second) and until 215,337 reading access in one second (IOPS), when writing up to 3,209 MByte/sec. and 114,580 IOPS (see comparison above). Most values are about twice as fast as that of the Transcend ESD380C (USB 3.2 Gen 2×2) and up to a good three and a half faster than that of the crucial X9 (USB 3.2 Gen 2). Only when writing does the Extreme Pro have accessed at a somewhat braked pace – the sandisk creates “only” 114,580 IOPS as written – is therefore better than the crucial with 99,482 IOPs, but minimally slower than the transcend with its 116,096 IOPS. This could be due to a bug in the firmware of the USB4 control chip on the main board of the SSD, because this noticeable weaker measurement result also occurred in the test laboratory of Computer Bild with a self-made USB4 SSD. Therefore, the values of the Extreme Pro could improve again when accessing writing if the manufacturers revise the firmware or driver for USB4.
Test conclusion Sandisk Extreme Pro USB4
More often has to cover up large amounts of data, benefits from the extra speed of the Sandisk Extreme Pro USB4but then has to be ready to spend about twice as much as for a conventional model with USB3.
