1d ago

What SATA (or PCIe+adapter) SSD for a Debian laptop?

Basically want something with decent performance and durability. Cost matters, but I'm not trying to hit rock bottom. I'm particularly wondering, is an HMB-type PCIe SSD ok combined with a SATA adapter? I think HMB is supported if your machine can use a PCIe or NVMe disk directly, but I'd be using an older Thinkpad with a 2.5" SATA slot at least for now. So I'm wondering if I'd lose a lot of performance if the SSD combo doesn't have its own RAM buffer.

I see good deals by today's standards for PCIe SSD's at of all places, Office Depot.

Thanks.

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@solrize Well it could be worse, I still have an old Dell Inspiron with it's original 2.5" 3600 RPM ultra-slow hard drive. Now that the battery has finally given up the ghost, I am going to replace it with an SSD while I have it open to change out the battery, but because the nvme slot on this machine only supports a max of 500GB, I am going with SATA.

those things were designed to run off mechanical drives. so whatever you fit it with will be screaming fast. the bottlenecks you're concerned with arise with workstation-class machines with fully implemented PCI lanes and such, which are pretty rare in laptops. HMBs also require a beefier CPU as all that buffering introduces overhead; not noticeable on a 6-core Ryzen, noticeable on a dual-core decade-old i5.
summarum: whatever SATA SSD you fit it with is more than adequate. obviously, don't go with no-name "brands". also, save yourself the bother and don't dick around with adapters, just fit a regular SATA 2.5" SSD in there.
- Thanks, I think you have it right and that it's not worth messing with adapters. The adapter was never about performance from my perspective though. It was about being able to keep using the drive if I eventually moved to a laptop with an M.2 slot.

@solrize You want to use nvme rather than sata if possible, particularly if a high end ssd as the absolute max speed you can get with sata is 6gb/s and also using a sata ssd will often make one or two sata ports not function.
- I don't think I can use NVMe in my old laptop but yes, otherwise I'd do so. ;)

Whatever is a reliable brand that fits in your budget. Since you only have a SATA connection, you're maxed out at 600MB/s on your transfer rate. Buying a drive with faster benchmarked transfer rates won't give you any benefits.
- Thanks, I wasn't really thinking about transfer speeds, it's just the PCIe drives are cheaper (depending) and more re-usable if I get a newer laptop later. I think you are right though that it's not worth messing with adapters.
  I dunno if there's such a thing as a reliable brand. The brands have reliable and unreliable models. Particularly I have the idea that I should be avoiding QLC drives, but that TLC these days is ok.
  
  Samsung, WD, Seagate, Corsair...etc. Just not a random no-name brand. Poke around the Backblaze stats to get a good idea.

I think a SATA connection might be the bottleneck with its maximum throughput of 600 MB/s. So for that use-case you don't need to be worried about the SSDs speed and cache, it won't be able to perform due to the SATA slot. But I don't know how exactly you plan to repurpose it later. Maybe skip the adapter if it's expensive, buy a cheap SATA SSD now and a new, fast PCIe one in a few years once you get a new computer.
- The purpose of the cache is to improve latency and save SSD wear. It doesn't help much with throughput as far as I know. Although if it's on the host side, maybe it does.
  
  Is a SSD's cache even about wear? I mean wear only happens on write operations. And I would expect a SSD to apply the writes as fast as possible. Since piling up work (a filled write cache) means additional latency and less performance on the next, larger write operation. Along with a few minor issues like possible data loss on (power) failure.
  And on read, a cache on the wrong side of the bottleneck doesn't do that much. A SSD has pretty much random access to all the memory, it's not like it has to wait for a mechanical head to move into position on the platter for data to become available?!
  But I haven't looked this up. I might be wrong. What I usually do is make sure a computer has enough RAM and it is used properly. That will also cache data and avoid unneccessary transfers. And RAM is orders of magnitude faster, you can get gigabytes worth of it for a few tens of dollars... Though adding RAM might not be easily done on the more recent Thinkpads... I've noticed they come with a maximum of one RAM slot for some years already, sometimes none and it's soldered.

I am not aware of any SATA SSDs which use HMB, so I am not sure if it would work correctly through an adapter. I think the choice for 2.5" SSDs is generally between DRAM cache SSDs and ones with SLC caching, which are typically much cheaper. I think both are pretty much able to saturate the ~500MB/s bandwidth of a SATA III connection, but may run into issues with prolonged writes or when getting very close to full.
Looking on Newegg, for DRAM cache units, things like the Samsung 870 evo and Crucial MX500 cost ~$90 or so for the 1TB model.
SLC cache units like the Crucial BX500 or Team Group CX2 are much less, more like $50-60 USD. The Team Group one claims 800TBW endurance for the 1TB model. I do not know if I believe that, but generally speaking I have used their nvme drives before and have not had any fail on me, for what that small data point is worth.
- Newegg doesn't seem to sell the Crucial MX500 any more*, only the BX500. But if the 870 evo is comparable, I might get that, since I have a couple of MX500s now and am happy with them. I hadn't realized that Team Group was legit at all! I'll keep that in mind. Thanks!
  *Note: The MX500 appears on Newegg's web site, but the actual sellers are "Newegg Marketplace" randos rather than Newegg itself, and I prefer to buy directly from Newegg when possible.

I always use Samsung for my SSD drives. I bought my first Samsung 250 GB SSD back in 2017, only purchased Samsung SSDs since then. Not one has died yet.
You can get a Samsung EVO 870 (1TB SATA SSD) for ~90$ on amazon.
Debian will literally take any storage you throw at it anyway.
I do not know anything about HMB, does it really bring performance improvements, considering that SSD disks are pretty fast anyway?
- HMB is host memory buffer or something like that. It means instead of having a ram buffer in the drive, the OS software uses some of the host computer's memory for disk buffering. That makes the drive cheaper but I haven't heard claims of it being any faster. Consumer drives seem to all use it now, and Linux supports it, but maybe not when you wrap up the HMB drive in a SATA shell.
  I guess $90 for 1TB is pretty good. I have been suspicious of the EVO drives but at least they aren't QVO.
  Thanks!
  
  You're welcome!
  What's so bad about the QVO drives?
  but maybe not when you wrap up the HMB drive in a SATA shell.
  That makes sense, with HMB being an NVME feature. I tried searching for HMB and SATA, but did not find any information about if it will or won't work, so it's probably best to assume that it won't.

19 comments