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The AI858 is a PCIe 5.0 SSD winner from AGI with good all-around performance and an effective heatsink with relatively minor trade-offs.
Reasons to buy
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Good all-around performance
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Low random read latency
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Good sustained write performance
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Heatsink included
Reasons to avoid
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No software support
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AGI is probably not a brand you’ve heard of, but they make many memory products that are often sold at a discount. We reviewed the AI818 SSD two years ago with something less than enthusiasm, but we’re happy to say that AGI seems to have taken our critique to heart with the AI858. A budget, high-end drive is a bit of a contradiction, but in this atmosphere of skyrocketing memory prices, every dollar matters. If you can save a few bucks and still get a fast drive, you should, and that’s the segment the AI858 is targeting, but this time with hardware that’s actually good.
If you’re ever upset that a drive only comes in one or two capacities, then the TeamGroup G70 Pro might be for you. Not only does it come in both heatsinked and non-heatsinked versions, but it’s also available at 512GB, 1TB, 2TB, 4TB, and even 8TB. At the time of review, we could only find 1TB, 2TB, and 4TB, with pricing pretty close between the two types – go for the heatsink, if you can. We’re giving the lower prices at $197.99, $326.99, and $505.99. If you’re shooting for DRAM, these prices aren’t too bad, but we’d lean towards the Seagate FireCuda 530R instead at 1TB. The G70 Pro is more competitive at 2TB and 4TB against comparable drives.
The drive is capable of reaching up to 7,400 / 6,600 MB/s for sequential reads. AGI does not list the random read and write IOPS specifications, but we know this controller and flash combination tends to reach at least 700K and can reach 1,000K or more. This is comparable to other drives in this class. We wouldn’t recommend the drive at 512GB as it can’t reach peak performance. Ideally, you would go for 2TB or 4TB for the best results. The drive is backed by a five-year, 740TB of data writes per TB of capacity warranty, which is above average but not exceptional.
AGI offers no downloads aside from the spec sheet. For checking drive health information, we recommend CrystalDiskInfo. CrystalDiskMark, its sibling, is good for benchmarking your drive to make sure everything is working well. For backups and disk imaging/cloning, we recommend MultiDrive for Windows and either Clonezilla or Rescuezilla for other operating systems or for booting.
This is a double-sided drive with a heatsink. Great for desktops and, in a pinch, the PS5, but less great for anything else. Considering it’s a high-end PCIe 5.0 drive, that’s fine – you’ll be using this in an enthusiast desktop, most likely.
There’s not too much else interesting here unless you read the PCB silkscreen lettering beneath the rear label. This gives you information after the drive and its components – it’s using the Silicon Motion SM2508 (SM2508) controller in the M.2 (M2) form factor with LPDDR4 (LPD4) volatile memory, four NAND flash packages (4) in the BGA178 (178) form factor with an SMI reference design (Y260A), manufactured during week 23 of 2025 (25.23). This information could be useful to you in multiple scenarios: when you’re looking at review photos of drives, when you are checking a drive you purchased, or when you’re comparing drives.
The drive has the SMI SM2508 controller, as mentioned, with a single Samsung LPDDR4 DRAM memory module and four mysteriously-labeled NAND flash modules. The Samsung memory is low-power, which is good, and is in a 16Gb or 2GB configuration, which means the drive meets the usual 1GB:1TB DRAM:NAND ratio.
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Deciphering the flash is a little trickier, but we’ve discovered that this uses Micron’s 232-Layer TLC. This matches other “budget” SM2508-based drives that are using this flash rather than BiCS8 or 276-Layer Micron. It’s not a bad trade-off if you can get the drive for a little less money.
