Lexar NM1090 Pro Review – The Best Gen 5 SSD?

This is the Lexar NM1090 Pro, and this is as close to an unbiased review as I can do. I kinda hate the whole clickbait attention grabbing stuff that seems to be a requirement to make reviews these days, so instead I want to do something different. Be honest, show you the thing, test it, and give you my thoughts. If that sounds good to you, let’s get into it. Oh and disclosure, Lexar – or Lexar’s Chinese PR company anyway – provided me this drive to test, although they don’t have any say in the video, my thoughts or anything. These are my thoughts and test results. Right, the drive.

This is the “Pro” version of the NM1090, which means it doesn’t come with a heatsink, but is 2GB/s faster. They claim 14GB/s reads and 13GB/s writes – less than a gig slower than the Crucial T710 I checked out recently – although that’s only for the 2TB and 4TB versions, the 1TB ‘only’ hits 10GB/s on writes apparently. It’s a regular 2280 form factor, although at least this 4TB version is dual sided. Only partially dual sided, but still for some boards and laptops that might be an issue so do keep that in mind. As I said, this comes in 1, 2 and 4 terabyte capacities, and I’m happy to report this does have a DRAM cache, with both the 1 and 2 terabyte drives getting 2GB, while the 4TB gets 4GB. Where this story gets interesting is that while the DRAM and the NAND flash are both made by Longsys, a Chinese manufacturer, the controller is a Silicon Motion SM2508G – the same one Crucial uses in the T710. That is a fast quad core ARM chip that is a ‘true’ Gen 5 x4 controller, so performance between these two should be at least somewhat similar, although the differences in the NAND flash will play a role. Obviously with four NAND packages on this 4TB drive, each package offers 1TB of capacity, while Micron’s packages can offer up to 2TB per package. 

Anyway, that’s a look around the thing, now let’s get it in a system and test it out. Let’s start with the synthetic tests, and Crystal Disk Mark specifically. The top end best-case test is this one, the Sequential read and write with a queue depth of eight and one thread. This one sees the NM1090 a hair ahead in reads – like 30MB/s on 14,000 MB/s, although that is 173MB/s faster than claimed so that’s great. Writes are less impressive though at 12.5GB/s. That’s still amazingly fast of course, but isn’t the 13GB/s that Lexar claims, nor is it the 13.3GB/s the Crucial T710 offers. Still, it’s crazy fast. Swapping to the same test but with the queue depth of one, we see a very stark difference to the T710. The NM1090 offers nearly 9GB/s on writes – down from over 10GB/s on the T710 – but only 6GB/s on reads. That’s good Gen 4×4 SSD territory! Yikes. The tougher set of tests are the random 4K blocks ones, like this with a queue depth of 32, which really doesn’t look good for the NM1090. It’s mid-field, behind the NM800 and Lexar Thor Pro, at least on writes, although it is ahead of the T710 in both read and writes so there’s something. Happily with a queue depth of one the NM1090 Pro shines – at least on writes – coming in right at the top with a decent little lead over the T710. The reads aren’t much to write home about though.

AS SSD generally offers the same sort of standings, but lower results. As a perfect example, AS SSD’s best case test, the sequential read and writes, has the NM1090 at 10GB for writes and only 9.6GB/s on reads – a fair bit less than Crystal Disk Mark! It’s around 500MB/s slower than the T710, but still in a league of their own compared to all the other drives. As for the random 4K blocks, the NM1090 is still at the top, and actually doing pretty good on reads too. It’s slower than the T710 on reads, but a decent (if small) advantage in writes. The same test, but with 64 threads, doesn’t play out quite as well for the NM1090, matching the T710 in writes, but being decidedly mid-field in both reads and writes. It’s in the higher echelons for reads for sure, but not exactly top.

Finally for the synthetic tests, ATTO Disk Benchmark. This is a bit busy I know, but the two yellow lines are what we’re looking for here. This is performance across varying block sizes from 512 bytes to 64 megabytes, with a queue depth of four. The write performance looks to be about on par with the T710, up until 128KB blocks anyway, where it then diverges, offering generally lower performance overall. But we’ve seen that – it’s a bit slower on writes at the top end – that’s fine. What’s unusual is the read performance, where it follows the usual curve up to 64KB, then it flatlines, then picks back up at 2MB blocks, matching the T710’s performance. I don’t know what’s going on here, whether it’s a controller firmware issue, or a NAND limitation, but it isn’t amazing. 

As for file transfers, to be honest you’re going to struggle to saturate these things. PCIe Gen 5 – and especially four lanes of it – is just so fast that even stuff like a RAMDISK is going to struggle to stress this. My usual file duplication stress test does though, and the NM1090 does pretty well, although isn’t the best I’ve seen. It starts duplicating at 3GB/s, versus 3.3GB/s on the T710, although the party piece here is that this thing barely drops any performance despite literally filling the drive. After basically filling the drive – over 3TB of writing, it does drop to around 1.15GB/s, but you have to write 3TB of data at once to get that, so I’d call that a win. The drive does have three temperature sensors onboard, and while the primary temperature only hit around 60°c with a large motherboard heatsink on top, the “Drive Temperature 2” sensor did hit up to 81°c which is on the high side. The motherboard I’m using does actually have heatsinks on both sides too, so I don’t know if this is a smothering problem or is normal for a drive like this. Still, it didn’t thermal throttle, but it definitely needs a heatsink.

The true benefit this thing has over the T710 isn’t speed – it doesn’t even claim that crown – no it’s price. This 4TB drive is over £100 less than the 4TB T710 – which need I remind you has the exact same controller, and some very similar performance figures. While this thing isn’t quite a fast, for all intents and purposes it is, and for such a steep discount? Damn. This appears to be a fantastic value – for those dead set on a Gen 5 drive anyway – and offers near top-notch performance too. I personally don’t get why you’d buy a Gen 5 drive right now – you barely benefit from a Gen 4 drive right now – so I wouldn’t buy this, but only because I’d buy the Gen 4 version instead for another £100 less. Like, you can buy two 4TB Gen 4 drives for the same price as the T710… Anyway, I’m impressed with the NM1090 Pro, and if you are dead set on a Gen 5 drive, check this one out. It’s linked in the subscription if you want to check it out.