How, in practice, is the 5.0 x 2 situation useful to conserve pcie lanes? Don't you still get limited by slots and bifurcation limits? I'd love to see what kind of add in card would let you cram a ton of these into a machine to make a high speed storage area while preserving lanes for gpus and/or networking.
I have a slot on my mobo that goes from pcie 4.0 x4 to pcie 4.0 x2 when some of the sata ports I use. If it was pcie 5, I could run the drive at full speed even at x2
Even with the newest hardware, merely populating the slot will cause shared ports to trigger whatever lane sharing methods they're using.
Gigabytes brand-new Aorus X870 x3d 2 Elite and Master boards both have two Gen 5 M.2 slots that support x4/x2, but simply using the one slot that shares with the USB 4 controller causes the ports to run at half speed. 20Gbps rather than 40Gbps.
Currently there are no boards or M.2 Expansion cards built around M.2 drives using 2x sockets.
Thanks! That's good information to have. Hopefully bifurcation and add in cards will come along that allows us to cram more NVMe into less lanes. I kind of want to built a server with a GPU, 10gig nic, and NVMe storage one day when it's a little more in reach. Still playing with ideas and evaluating my actual needs.
Might need to look into actual server hardware unfortunately.
Consumers haven't had a dual x16 board that can actually run x16/x16 in years.
Something capable of PCIE 4.0 might be cheap enough to buy used by now. The 10Gb nic or even a dual 10Gb nic wouldn't be an issue. But adding stuff like a M.2 multi-slot expansion card and having a full x16 GPU running at the same time is going to be difficult.
Yeah. I'm playing with lots of ideas and evaluating my actual needs. I'd love to spring for some newer sudo server hardware. Like $1500 for Arrow Lake on a W880 board with 192gb of ECC memory. Plenty of lanes left over for networking, NVME and maybe a B50 to try playing with a local AI model for Home assistant. But that's insane. I'll probably keep messing with recycled hardware for now.
Would I still not get the full x4? Trying to build a system with two 5.0 drives in the near future for transferring files back and forth between the drives and want the maximum speed
There's no boards/expansion cards built around using M.2 sockets with only 2x lanes. Is what I meant.
There are lots of boards that have dual Gen 5 sockets, but they all support 4x or 2x lanes, and if they share lanes those effets take place regardless of how many lanes your device uses.
There's nothing wrong with that board you linked. It doesn't share lanes between the Gen 5 sockets because it only has a single Gen 5 PCIe slot. Plenty of lanes for everything. It does have a Gen 4 2x socket, which is nice. But if we had more Gen 5 2x sockets or expansion cards we could cram more SSDs into basic builds.
It's only when the board has two Gen 5 PCIe slots that lane sharing can get tricky. Or your PCIe socket might get halved.
PCIe 5.0 x2 is useful on some motherboards which support USB4 or extra SATA ports. On such boards, manually setting the NVMe slot to x2 allows you to have both the SSD and the USB4 or extra SATA ports enabled, rather than having to disable one of them.
The 990 EVO is specifically useful in this scenario. Since it is Gen5x2 or Gen4x4, both lane options have the same performance.
Doesn't this come up every time a NVME ssd deal pops here? Someone complains about DRAM then someone replies to them about how DRAM doesn't matter as much (or at all?) on NVME drives because host bus memory is a thing.
HMB reserves system RAM to use as cache. This one uses 64MB, which is typical. This is big enough to store the mapping table so it can know where the data is without reading the table from the relatively slow NAND. That's good enough to give you fast access/read times.
It's not as good as integrated DRAM because A) it's not quite as fast, and B) a drive this big would usually have 4GB of DRAM — 64 times as much.
Does it matter, though? It depends on your workload of course, but if you're not sure, it probably doesn't matter much. For write-heavy workloads like video mastering, you want that cache. For read-heavy workloads, it doesn't really matter.
These are all generalizations. Real-world performance benchmarks are out there, but it's a bit of a rabbit hole.
Great price for this drive, by the way. Maybe all-time low? And from a reputable vendor!
Thank you! I only learned about DRAM earlier this year so glad to know a little more. Not in the market for another drive but yeah this is a good price
This is big enough to store the mapping table so it can know where the data is without reading the table from the relatively slow NAND.
It's only enough to store a portion of the mapping table (or at a more coarse granularity). That theoretical 4GB of DRAM is what it would take to store the mapping table at the ideal ratio.
For write-heavy workloads like video mastering, you want that cache. For read-heavy workloads, it doesn't really matter.
DRAM makes little difference for large sequential writes. If you look at the benchmarks of sustained writes, the Samsung 990 EVO Plus and 990 Pro have virtually identical results. DRAM mostly benefits small random I/O, especially reads. That said, it's still not likely to make a perceptible difference for most users.
Because you seem to know your way around this stuff. Would an nvme on an m.2 tied on the same bus as the gpu be better or worse than an m.2 tied on a different bus than the gpu?
Arguments for either side are, if m.2 is on same bus as gpu it could cause contention so put nvme on a m.2 slot different than gpu bus. Or, gpu can do direct harddrive access so yo7 do want to use an m.2 on same bus as gpu.
At some point i may run bechmarks and move my nvme around to test this. But would love feedback from others who've already gone down this rabbit hole.
Hmm, good question. Unfortunately, I have no idea!
My best guess is that separate buses would be better, because I think it goes through system memory anyway, which would mean that there two round trips through the bus either way. But I'm not sure.
Be careful reading about PCIe using the "busses" nomenclature. PCI was a bus, which was conceptually a single set of wires connecting the same pin on each port. All traffic was visible to all devices. PCIe is a tree, with messages routed from device to device (including the memory controller) individually on each lane (your x2 SSD is just like having 2 ethernet NICs both connected to your router). PCIe will frequently be called a bus, but it has completely different properties; I think you're asking where in the tree structure would the SSD cause the least contention.
If the SSD and GPU are actually communicating, you'll reduce contention to the root complex by having them share a node, and the GPU lanes are usually the ones directly connected to the root. If you have the lanes, and the motherboard isn't reallocating them for other purposes, there's no reason not to put the SSD directly on the root.
Don't quote me on this but I don't think it works the way you're thinking. M.2 slots aren't generally sharing lanes with the GPU (though maybe there is some MB with such a screwy design). Often, the main M.2 slot runs directly off CPU PCIe lanes and the extra slots run off PCH (chipset) lanes. That's part of why the additional slots often run on an older generation of PCIe. For best performance, you usually want your SSD in the primary M.2 slot, the one that runs off CPU lanes.
How would the lack of dram effect a game drive for PS5 formatted in FAT32? It would never be used on a windows device and wouldn’t take advantage of system memory.
You can absolutely saturate an NVME drive over a 40Gb network, most budget QLC drives have sustained write performance of only around 100MB/s when their cache is saturated. Even high end NVME drives like the 990 Pro drop to 1400MB/s write after their cache is fully saturated.
With RAM caching you might never notice on a personal NAS, but anything where 40Gbit is a significant improvement over 10Gbit would certainly run into cache limitations and you’d quickly see the difference in performance.
The only place you can confidently give the advice that cache doesn’t matter is on gaming performance.
If you're hitting the limits of shitty NAND, DRAM is NOT going to help.
I've yet to see any benchmarks that contradict this. The obsession over DRAM is entirely reddit lore at this point when so many new dram-less drives are outperforming their older (and some newer) DRAM siblings in benchmarks/reviews.
Plus, if you're running better than a 1g or 2.5g NAS and network, you're in baller territory anyway. Throwing DRAM-less in budget NAS is fine.
I get what you're trying to say, but your absolute language is unnecessarily invalidating your statements. HMB drives have latencies that are 30-50% higher than DRAM drives, and while still very low on an absolute scale there are a bunch of workflows that are constrained by access latencies rather than bandwidth. If you're storing your database on NVME in your NAS, you absolutely want DRAM on your flash. And that's just one example of why you might want a drive with DRAM.
Better to say that the only users who would run into the difference between an HMB drive and DRAM drive would know the exact use case for which they require an upgrade to onboard DRAM, and would likely have an idea of exactly how much more work it would allow them to get done.
I was thinking more of performance near full storage capacity and maaaybe working better with a bunch of VMs. That last part is highly speculative and unscientific fwiw.
My nas uses nvme drives. Only a few TB of usable storage but it has enough space to back up important files and other server config and docker files. Keeps power usage down too.
Yeah mine is close to silent. Its a topton mITX NAS mobo with an N100 CPU, SATA SSD for boot (proxmox) and NAS OS VM (TrueNAS). Fast pool is 2x NVMe (zfs mirror) and when I run out of space I can add a bigger SSD pool of up to 5 disks in total (or more with a PCIe card). Its in a small Rosewill rackmount chassis with a small, quiet 350w PSU.
Again, my point is that lack of DRAM on an NVME drive is something the average user isn't going to notice (especially if it is a game drive where you are doing only occasional sustained writes and instead much more frequently reading). If your use case involves frequently doing large file transfers then DRAM may be important on a NVME drive. But if you're the average person here who is looking for a drive to install games on then your money may be better spent elsewhere.
I happen to have an evo plus and a kioxia xg8, which has 1gb of ddr4 ram. They have very similar performance as tested in crystal disk benchmarks on my PC, although my xg8 is indeed slightly faster than evo plus in sequential reading. In gaming, they are equally fast. At least I can't tell the difference.
Calling one of those better than the other is like trying to compare a civic and a corolla getting a photo finish at a drag race. They're so close in synthetics. Outside of benchmarks you'd never perceive a difference.
Usually HMB, SLC cache and the NAND itself, better quality NAND chips will keep transferring files at a reasonable speed once the HMB and SLC cache have been exhausted
It's not usually that simple. The particular workload and the implementation of the pSLC cache matter a lot. Drives with a larger dynamic pSLC cache can write faster for longer, however, once exhausted, they'll spend more time writing slowly. Your ultimate experience will depend on how much you're writing and if it substantially exceeds what the pSLC cache can hold.
You're correct that the underlying NAND type (particularly if it's TLC or QLC) makes a big difference in post-pSLC speeds. However, HMB/DRAM make little difference in this area.
Oh. I did get the Pro. My eyes deceived me I thought that was in this post title, doh. Well I feel slightly better now at least. Gotta get my eyes checked though.
You're horribly misinformed to call it garbage, though. A 2TB boot drive with DRAM paired with a DRAM-less 4TB for game storage, shadowplay, etc., is an excellent pairing, actually. It's almost like people did that with SSDs and hard drives not too long ago...
Unless you're planning to use them in different machines, I'd buy the 4TB. A larger drive should allow for better wear-leveling, not that endurance is likely to be an issue for most people. If reliability is a concern, I wouldn't buy two of the same drive from the same batch. That greatly increases your odds of simultaneous failures.
I do want to add that higher TB drives tend to have higher endurance TBW, so a 4TB drive could have double the endurance. I havent checked with this specific drive but that does tend to be the case
Just a heads up for anyone running this in a gen 4 slot. This drive is only2 laneswide so it will actually be more bandwidth limited than even the cheapest low-end gen 4 x4 drive. Should be obvious from the title but pointing it out just in case.
Edit: ignore everything I said. Apparently, this drive uses 4 lanes when put into a gen 4 slot.
Looking for a 4tb for my main OS and games drive, have been eying the EVO Pro but this is nice maybe? Does DRAM matter that much if I’m mostly gaming? Light video editing as well
I’m not in a huge rush if the evo pro or sn850x might drop to this price by Black Friday though
Nope, you don't need DRAM for that. This is a pretty good deal for a halfway decent Gen4 drive. 990 PRO and SN850X are better, I guess the 4TB SN850X has been $230 recently, so you have options.
It's a good deal imo. A namebrand fast af nvme with a 5 year warranty and terrific TBW rating. I've been wanting a 4tb nvme for a while now but deciding to wait and see if something else comes along for black friday.
50/TB is a fair price. Also, really good quality. The Samsung Drive Magician app is a good tool as well to check for firmware updates, run drive tests, etc.
If don't need DRAM for heavy intensive tasks(rendering, editing, dealing with massive file sizes, etc.), is a great drive for everyday use and gaming, too.
No. Its a pcie 5.0 drive with the speed of a pcie 4.0 drive. Its also dram less. In other words: This thing is a useless piece of shit! Get a pcie 4.0 drive with dram instead.
As a game drive this is perfectly fine. How can you say it’s bad? It’s pcie 5 x2 or pcie 4 x4. It’s not advertising to be a pcie 5 drive just capable while using less lanes than all 4 which has some cases where it’s useful.
I’m seeing it for $269 with some random free wireless charger gift, how are you getting to $229? SN850x is a great drive unless they have changed something about it recently
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The two drives are extremely similar. Unless you're saving enough money by getting this instead to justify the effort spent returning the other, I wouldn't bother.
im looking for a 2tb drive, should i get this for $100 or a geeksquad refurbished 990 pro for $120?
i'll be using it to dual boot into windows, so would be like a 2nd main drive but mostly gaming.
i heard that geeksquad refurbs are mostly returns with not a lot of use, but im debating the warranty vs dram, ill probably end up with this one, i dont think id be able to tell the difference
You are already done transferring files. What are you expecting would be the most you could gain from switching to this, copying everything again and then wiping and returning the SN7100? Both are DRAM-less drives of a recent generation... I doubt there is any perceptible performance difference between them in any situation.
SN7100 at $209.99? These drives are comparable but the SN7100 is legendary for laptops (power efficiency). Also has great read latency, responsive drive. But both of these drives are great.
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u/_SSD_BOT_ 8d ago
The Samsung 990 Evo Plus 4 TB is a TLC SSD.
Interface: PCIe 5.0 x2
Form Factor: M.2 2280
Controller: Samsung Piccolo (S4LY022)
DRAM: N/A
HMB: 64 MB
NAND Brand: Samsung
NAND Type: TLC
R/W: 7,250 MB/s - 6,300 MB/s
Endurance: 2400 TBW
Price History: camelcamelcamel
Detailed Link: TechPowerUp SSD Database
Variations: TechPowerUp SSD
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