Samsung's 990 Evo is the world's first hybrid PCIe 4.0 x4 and 5.0 x2 SSD — FrankenSSD has two different interfaces with two different lane widths
Samsung's first PCIe 5.0 NVMe SSD?
Samsung has accidentally published the product page for its upcoming 990 Evo NVMe SSD, complete with marketing and hardware specifications (via WinFuture). Although Samsung is mostly known for making top-end SSDs like its 990 Pro, the 990 Evo is a firmly midrange drive thanks to its reads and writes of just 5,000MB/s and 4,200MB/s respectively. However, the 990 Evo is unique in its four PCIe 4.0 lanes / two PCIe 5.0 lanes configuration.
Perhaps the 990 Evo's most unique selling point is that it supports PCIe 5.0, but only with two lanes, which is equivalent to the bandwidth of the four lanes of PCIe 4.0 that it also offers. PCIe 4.0 SSDs work completely fine on PCIe 5.0 slots, so there's technically no advantage for the 990 Evo to support PCIe 5.0, especially when it's not even bottlenecked by its PCIe 4.0 connection.
Row 0 - Cell 0 | 990 Evo 1TB | 990 Pro 1TB | 970 Evo Plus 1TB |
Form Factor | M.2 2280 | M.2 2280 | M.2 2280 |
Interface | PCIe 4.0 x4/PCIe 5.0 x2 | PCIe 4.0 x4 | PCIe 4.0 x4 |
Sequential Read | 5,000MB/s | 7,450MB/s | 3,400MB/s |
Sequential Write | 4,200MB/s | 6,900MB/s | 2,500MB/s |
Random Read | 680K IOPS | 1,200K IOPS | 500K IOPS |
Random Write | 800K IOPS | 1,550K IOPS | 450K IOPS |
Security | TCG/Opal 2.0 | TCG/Opal 2.0 | TCG/Opal 2.0 |
Part Number | MZ-V9E1T0BW | MZ-V9P1T0BW | MZ-V75S1T0B |
However, there is a niche scenario where these two PCIe 5.0 lanes would come in handy. Although the bandwidth for two PCIe 5.0 lanes and four PCIe 4.0 lanes both are 8,000MB/s, there is a difference if the data connector only has two lanes. On a PCIe 5.0 interface with two lanes, a PCIe 4.0 SSD will only be able to use two lanes and would see its bandwidth cut in half from 8,000MB/s to 4,000MB/s.
By contrast, the 990 Evo would be able to retain its normal bandwidth since it can run those two lanes at PCIe 5.0 speeds. Additionally, running two lanes instead of four could also save a little power. However, as a consumer drive, it's hard to see how these PCIe 5.0 lanes will actually be useful. Desktops have plenty of PCIe 4.0 M.2 slots with four lanes to go around, and no laptops support PCIe 5.0 yet. We haven't seen any other brand support two different versions of PCIe like this, and it's curious why Samsung didn't simply use four PCIe 5.0 lanes.
Although you'd expect some pretty impressive gains after five years, the 990 Evo offers only a fairly modest uplift compared to its predecessor. Part of this is probably down to the fact that the 970 Evo Plus was already a pretty fast SSD for its time, and brushed up against the limit of the PCIe 3.0 interface. By contrast, the 990 Evo gets nowhere near the ~8,000MB/s limit of PCIe 4.0 with four lanes. Instead, the 990 Pro continues to be Samsung's flagship PCIe 4.0, with the 990 Evo slotting in between it and the 970 Evo Plus.
Samsung hasn't revisited its more midrange and affordable Evo lineup since the 970 Evo Plus in 2019, which only came with support for PCIe 3.0. Back then, the 970 Evo Plus was pretty high-end even though 2019 was also the year the first PCIe 4.0 SSDs were introduced. Ever since however, Samsung has continued to make more 970 Evo Plus drives, and they've largely become the company's low-end SSD.
WinFuture noted that Amazon Germany had prices listed for the 990 Evo, which were a little more expensive than the 990 Pro. Those prices have since been removed, and although it's not clear why, we can probably safely assume Samsung won't launch a midrange SSD that has an MSRP higher than the price of its flagship.
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Matthew Connatser is a freelancing writer for Tom's Hardware US. He writes articles about CPUs, GPUs, SSDs, and computers in general.
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Alvar "Miles" Udell WinFuture noted that Amazon Germany had prices listed for the 990 Evo, which were a little more expensive than the 990 Pro. Those prices have since been removed, and although it's not clear why, we can probably safely assume Samsung won't launch a midrange SSD that has an MSRP higher than the price of its flagship.
I guess with Samsung and the other manufacturers colluding to slice production in order to increase prices they see a price segment for a new Evo drive, likely where the Pro is now before prices increase. -
wakuwaku Desktops have plenty of PCIe 4.0 and 5.0 (????) M.2 slots with four lanes to go around
no they don't. Are you an AI hallucinating the future of desktops having alot of pcie 5.0 lanes? because that future is not here yet unless you are using hedt. And if you can afford hedt systems, you can sure afford way better drives than samsung evo ssds. -
sininspira Another scenario of having four 4.0 lanes or two 2.0 lanes is conservation of PCIe 5 lanes in certain motherboard chipsets...for instance a mobo with 20 max PCIe 5 lanes could then use x16 in the GPU slot and two x2 SSD drivesReply -
bourgeoisdude
That's what I was thinking. Using just 2 PCIE 5.0 lanes means more lanes for the other PCIE 5 connected devices. Still a very niche use case for consumer market anyway.sininspira said:Another scenario of having four 4.0 lanes or two 2.0 lanes is conservation of PCIe 5 lanes in certain motherboard chipsets...for instance a mobo with 20 max PCIe 5 lanes could then use x16 in the GPU slot and two x2 SSD drives -
thestryker Ever since we've gotten PCIe 4.0 having x2 drives available has made sense, but we haven't really seen them. Hopefully the additional cost is negligible, because I'd like to see this as the way forward. If we're going to be stuck with M.2 for desktop it might as well be in. fashion that allows for maximizing storage capacity.Reply -
usertests By contrast, the 990 Evo would be able to retain its normal bandwidth since it can run those two lanes at PCIe 5.0 speeds. Additionally, running two lanes instead of four could also save a little power.
They should call it the 990 Eco because it's Eco-friendly. -
domih
Yep.wakuwaku said:no they don't. Are you an AI hallucinating the future of desktops having alot of pcie 5.0 lanes? because that future is not here yet unless you are using hedt. And if you can afford hedt systems, you can sure afford way better drives than samsung evo ssds.
There is also the question about where the PCIe lines connect to. Direct CPU or via the chipset?
Finally, it will be interesting to see if there will be a Chinese OEM making a Gen 5 x4 x 1 --> Gen 5 x2 x 2 adapter to use two of these NVMe on one M.2 slot. The 4 lanes are there, so there would be no need for a multiplexer, though the motherboard BIOS will need to provide the option of x2 x 2 instead of x4 x 1. Unrealistic IMHO. -
thestryker
You'd still need it unless the slot supports bifurcation which to my knowledge no M.2 slots currently do. I sure wish consumer platforms all had better bifurcation support, but currently only the CPU provided lanes do (Intel it's limited to x8/x8 and AMD can do x4/x4/x4/x4) and none go down to x2.domih said:Finally, it will be interesting to see if there will be a Chinese OEM making a Gen 5 x4 --> Gen 5 x2 x 2 adapter to use two of these NVMe on one M.2 slot. The 4 lanes are there, so there would be no need for a multiplexer. -
sfjuocekr There is a reason why two lanes is better, it saves two lanes and the device can still switch off a lane when not required.Reply
You are still restricted to the amount of lanes exposed from the CPU, so if you can use less you also need to switch (context) less. -
Notton How does it work?Reply
If it runs at 2x5.0, then is it stuck at 2x4.0~1.0, or can it switch to 4x4.0 on the fly?
To me, it seems like a marketing ploy. It's "technically" a PCIe 5.0 NVMe SSD, but it's speeds are similar to budget 4.0 drives.
There is no desktop or laptop CPU that would benefit from "only" using 2x lanes, because none of them support 2x bifurcation. The CPU will allot 4x lanes and the other two lanes would be unused at 5.0 speeds.
Do server or HEDT CPUs support 2+2+2+2+2+2+2+2 bifurcation?