Sabrent Rocket Q4 review: Unusually small, surprisingly powerful

In one look

Expert rating

Benefits

• Versatile small form factor
• Incredibly fast performance
• Decently affordable
• Full five-year warranty

The inconvenients

• Writes slowly in a crawl when the secondary cache is exhausted

Our opinion

Sabrent’s 30mm long Rocket Q4 fits into devices that can’t handle a full 2280 SSD, but still provides up to 2TB of capacity. Best of all, its real-world performance is incredibly excellent.

Best Prices Today: Sabrent Rocket Q4 NVMe SSD

Sabrent’s Rocket Q4 is a half-size (37.5% actually), 2230 (22mm wide, 30mm long) NVMe SSD. Because it’s so small, it can be used in devices, such as a Steam Deck or Mini PC, that lack space for a full 2280 SSD.

But the real news is that it’s blazingly fast in the real world, even compared to PCIe 5.0 drives. Skeptical? We were. But when extended testing yielded the same outstanding results, we were more than pleasantly surprised.

Further reading: Check out our roundup of the best SSDs to learn more about competing products

Design features

I have already mentioned the small dimensions of the Q4. It’s also a PCIe 4.0, NVMe 1.4 SSD that uses Micron’s brand new N48 QLC NAND and Phison’s latest E21T controller. I bring them up because they’re the reason for incredibly easy real-world transfers, far surpassing any previous PCIe 4.0 SSDs we’ve tested.

The Q4 is also a non-DRAM HMB (Host Memory Buffer) design. In other words, it forgoes using DRAM for the main cache (there really isn’t any room to install it) and instead uses your system’s memory for this task.

HMB is a relatively new and inexpensive technology that improves with each iteration. Of course, its effectiveness will depend somewhat on the speed of your memory subsystem. Our new test bed with its faster 4800MHz DDR5 memory will definitely deliver higher HMB numbers than the older 3200MHz DDR4 system, so you can’t directly compare the results with our older HMB reviews.

On Amazon US and Amazon UK at the time of this writing, the Q4 is available in $44.99 / £49.99, $76.49 / £69.99, $109.99 / £149.99 and 219 $.99 / £339.35 for 256GB, 512GB, 1TB and 2TB capacities with the biggest on test here. It’s not a bargain, but it’s not a high price either. Considering the small form factor and performance, it’s a bargain.

Sabrent guarantees the Q4 for five years without reservation (two years without registration). Unqualified is a good thing because the TBW (terabytes that can be written to) rating for the 2TB SSD is a tiny 450 TBW. That’s a fair amount of data in the grand schema, but less than half of the norm.

If you’re unfamiliar, the TBW rating can be used like the mileage of an auto warranty, ending the coverage period sooner if exceeded.

In this case, Sabrent says it honors the warranty period no questions asked, only refusing users who attempt to run scams such as putting a Sabrent tag on another cheaper drive. Yes, there is always someone!

Performance

There was a huge gap between the Q4’s synthetic benchmark results and its times in our 48GB and 450GB transfers. At least in the context of the previous SSDs we’ve already reviewed. Synthetics showed the Q4 to be what it apparently is: a mid-tier QLC PCIe 4.0 SSD.

However, the Q4 blasted through our actual 48GB and 450GB transfers almost as fast as the incredibly easy PCIe 5.0 Crucial T700, and actually beat the Gigabyte PCIe5 10000 by a healthy margin.

Talking to Phison, it looks like Micron’s new N48 NAND is just blazing in pSLC (pseudo Single Level Cell/1-bit) mode and the E21T controller itself improves HMB performance. Whatever the reason, we did indeed see sustained real-world transfer speeds with the Rocket Q4 that we’ve only seen with the latest PCIe 5.0 drives.

The CrystalDiskMark 8 numbers listed below are certainly nothing special, and barely the best we’ve seen from a PCIe 4.0 SSD. Note how much faster the PCIe 4.0 WD SN850X seems to be.

But our jaws nearly hit the ground when we ran the 48GB transfer tests. The Q4 took second place out of all the drives we tested, far surpassing the WD SN850X, our previous PCIe 4.0 drive.

Jaws dropped even more when we saw the result of writing 450GB. The Q4 actually replaced the previously undefeated T700. Yeah. The Rocket Q4 is the fastest single SSD at this task we’ve ever tested. Amazing to say the least.

Note however that 450GB is usually not enough to exhaust the secondary cache on a 2TB or larger SSD these days, so we resort to additional 450GB writes to the secondary cache. East exhaust. Despite the graph, the test is less about speed and more about the quality of secondary caching and native NAND write speed when depleted.

Also, the results above were all collected using a blank, empty 2TB drive. Whenever the Q4 ran out of secondary cache (pSLC), writes would drop precipitously below 100 Mbps. Yeah. This would be after several long writes and/or smaller writes with the drive not having time to clear the cache by writing the data back to native 4-bit QLC mode. Dropping will also happen much sooner with lower capacity models.

The reason QLC is so slow when writing natively is the finesse and error checking needed to accurately store any of the 16 voltage levels in a cell. But be aware that this is a writing phenomenon only. Read speeds remain relatively constant, regardless of the amount of data on the disc.

Verdict

For those with average needs and for most applications, the Sabrent Rocket Q4 is a wonderful drive with incredibly fast sustained real-world performance. At least in 2TB capacity.

If you don’t have PCIe 5.0 or are not constantly writing very large amounts of data, this should definitely be at the top of your shortlist, even if you have room for a 2280 model.

How we test:

Internal drive tests currently use Windows 11 64-bit running on an X790 (PCIe 4.0/5.0) motherboard/i5-12400 processor combo with two Kingston Fury 32GB DDR5 4800MHz modules (64GB memory total). Intel integrated graphics are used. The 48 GB transfer tests use an ImDisk RAM disk occupying 58 GB of the 64 GB of total memory. The 450 GB file is transferred from a 2 TB Samsung 990 Pro which is also running the operating system.

Each test is performed on a newly formatted drive and TRIM so that the results are optimal. Note that in normal use, as a drive fills up, performance decreases due to less NAND for secondary caching, as well as other factors.

Disclaimer: The performance figures shown apply only to the drive shipped to us and the capacity tested. SSD performance can and will vary by capacity due to more or fewer chips for shotgun reads/writes and the amount of NAND available for secondary caching. Vendors also occasionally swap components. If you ever notice a significant discrepancy between the performance you feel and the performance youth reportby all means, let us know.