Multiple SSD question.

[Hypasonic]

Hello.

Question regarding multiple SSD's.

I currently have an m.2 nvme ssd (1TB) and a HDD (4TB) but the m.2 is basically full and I have this (probably stupid) mentality that I don't want to play any games that I can't have on my m.2 nvme SSD due to loading times and such so I don't bother installing them and therefore not play them. So I would like to get another SSD to fit more on, but I have heard/read that adding more SSD's will slow them down as they share the same connection/bandwidth or something.

I have an aorus z390 ultra motherboard, I know it has multiple nvme slots but I would just like to know if installing another m.2 nvme would slow the other existing one down, and by how much (maybe its negligible?) or alternatively would getting a standard SSD be better assuming that won't affect the speed of the m.2 nvme?

I've read things here and there from various sources and I think I'm just confused so any help would be appreciated.

Thank you.

[Hellobolis]

your SSD being full probably slows it down more than having more than one if you just use them to play games.

[Flame6]

eh, it might make one of them slower. I would GUESS that it'd be the one not being used for the game you're playing. I have 2 Sata SSDs and a m.2 and i havnt noticed a slowdown on any of them.

[Thayne]

Looking at this particular motherboard's specs, only the third PCI Express slot (PCIEX4) shares bandwidth with the M2P connector. This means that this slot operates at (up to) x2 mode when you have a M.2 SSD installed in any of the three connectors available. You won't lose any performance installing and playing from additional M.2 SSDs. The SATA SSD is also still a legitimate option for you, although it is relatively a little slower but nothing compared to downgrading to an HDD. I don't see any reason why you wouldn't just fill the other M.2 slots up first.

[Thunderball]

Hello.

Question regarding multiple SSD's.

I currently have an m.2 nvme ssd (1TB) and a HDD (4TB) but the m.2 is basically full and I have this (probably stupid) mentality that I don't want to play any games that I can't have on my m.2 nvme SSD due to loading times and such so I don't bother installing them and therefore not play them. So I would like to get another SSD to fit more on, but I have heard/read that adding more SSD's will slow them down as they share the same connection/bandwidth or something.

I have an aorus z390 ultra motherboard, I know it has multiple nvme slots but I would just like to know if installing another m.2 nvme would slow the other existing one down, and by how much (maybe its negligible?) or alternatively would getting a standard SSD be better assuming that won't affect the speed of the m.2 nvme?

I've read things here and there from various sources and I think I'm just confused so any help would be appreciated.

Thank you.

No, on all modern motherboards first M.2 slot is supplied by PCIe lines from the CPU, all others are supplied off the PCH (chipset), so no, it wont slow anything down. However, depending on a motherboard installing more SSDs will do some/either of:
- Disabling some SATA ports.
- Reducing bandwidth/disabling secondary PCIe ports.
- Reducing bandwidth/disabling secondary M.2 slots (if your motherboard has more than two).
- Also note that on some motherboards secondary M.2 slots might not have NVMe capability.

You can get either a SATA 2.5" SSD or a secondary M.2 SSD (SATA or NVMe) if none of the points above are concerning for you. You can always find what happens if you populate secondary M.2 slots in the motherboard manual.

If you're looking for particular models: Crucial MX500 is a good choice for both 2.5" and M.2 SATA SSD, and for a secondary NVMe SSD you can look into something with QLC NAND, like Crucial P1.

[Shakadam]

One NVME SSD won't slow down simply because you install another NVME SSD, no.

The drives would share the same bandwidth link to the CPU so yes you can cause them to bottleneck each other so to speak, but only by hammering both drives at the same time with heavy reads/writes which is unusual to say the least in a gaming PC. It will never happen while playing games but something like moving large amounts of data from drive A to drive B, and at the same time from drive B to drive A would probably saturate the link speed and you'd notice some slower speed, but that's not exactly a realistic scenario for most people.

- - - Updated - - -

No, on all modern motherboards first M.2 slot is supplied by PCIe lines from the CPU, all others are supplied off the PCH (chipset), so no, it wont slow anything down.

This is only true for AMD. Intel's current CPU's still only have a total of 16 PCI-E 3.0 lanes + the DMI 3.0 link to the chipset. All storage on a Z490 motherboard is routed through the chipset and the chipset - CPU link.

[Thunderball]

This is only true for AMD. Intel's current CPU's still only have a total of 16 PCI-E 3.0 lanes + the DMI 3.0 link to the chipset. All storage on a Z490 motherboard is routed through the chipset and the chipset - CPU link.

All the storage is routed through the chipset on all boards. The platform architecture is the same except for how the memory bus works (with Intel you have two buses and on AMD it's all IF). The difference is just how the depict it on block diagrams.

[Aleksej89]

Game loading speeds on modern SSD are so insanely fast that this issue is more of a psychological problem than a technical one.

Even if adding a 2nd SSD slows down the first SSD in terms of game loading times it would be imperceptible, perhaps even less than a second.

[Shakadam]

All the storage is routed through the chipset on all boards. The platform architecture is the same except for how the memory bus works (with Intel you have two buses and on AMD it's all IF). The difference is just how the depict it on block diagrams.

Not sure I follow what you mean here.

For Intel 10th generation CPU's you have 16 PCI-e 3.0 lanes (for the GPU/Primary PCI-e x16 slot) and a DMI 3.0 link (equivalent to PCI-e 3.0 x4 in bandwidth) to the chipset.

For AMD Zen CPU's you have 16 PCI-e 3.0/4.0 lanes for the GPU/Primary PCI-e x16 slot, 4 PCI-e 3.0/4.0 for the chipset link, and 4 PCI-e 3.0/4.0 lanes for the primary (m.2) storage slot.
Those 4 lanes for the primary storage slot isn't routed in any way via the chipset.

Intel's 11th gen, i.e Rocket Lake-S, adds another 4 PCI-e lanes to the CPU and doubles the DMI link to x8 speed, which brings them to parity with the Zen2/Zen3 CPU's. But, well, Rocket Lake-S isn't out yet.
Some of the current Z490 boards has a m.2 slot which is connected directly with the CPU like AMD motherboards, but that slot is disabled for now since current Comet Lake-S CPU's don't support it. It's just there for future considerations, meaning Rocket Lake-S.

[Thunderball]

Not sure I follow what you mean here.

For Intel 10th generation CPU's you have 16 PCI-e 3.0 lanes (for the GPU/Primary PCI-e x16 slot) and a DMI 3.0 link (equivalent to PCI-e 3.0 x4 in bandwidth) to the chipset.

For AMD Zen CPU's you have 16 PCI-e 3.0/4.0 lanes for the GPU/Primary PCI-e x16 slot, 4 PCI-e 3.0/4.0 for the chipset link, and 4 PCI-e 3.0/4.0 lanes for the primary (m.2) storage slot.
Those 4 lanes for the primary storage slot isn't routed in any way via the chipset.

Ofc they're routed via the chipset. The CPU cannot operate with any storage devices without the PCH. The only difference is that primary storage on AMD is not configurable, you always have those lanes dedicated to the M.2 slot. PCIe lanes just mean that there is a direct physical connection to the CPU, the operation is still controlled by the PCH. External controller are a bit more complicated but let's not get into that.

Intel's 11th gen, i.e Rocket Lake-S, adds another 4 PCI-e lanes to the CPU and doubles the DMI link to x8 speed, which brings them to parity with the Zen2/Zen3 CPU's. But, well, Rocket Lake-S isn't out yet.

DMI is just a protocol. Physically it's the system bus, i.e. the PCIe lanes.

Some of the current Z490 boards has a m.2 slot which is connected directly with the CPU like AMD motherboards, but that slot is disabled for now since current Comet Lake-S CPU's don't support it. It's just there for future considerations, meaning Rocket Lake-S.

I wouldnt be so sure how they're going to solve that. Are they going to connect the storage to the ringbus? IF shows it's advantages and disadvantages here. On one hand ringbus blows it out the water when it comes to bandwidth and latency, on the other hand there's no way to connect all pieces of the platform to it, you have to use the abomination that is DMI.

[chazus]

Regardless of bandwidth, pipelines, cache, whatever...

1) They 'act' of having two SSDs doesnt slow them down.
2) The only way you could slow down their performance is by having both of them transferring a great deal at the same time. Which.... won't happen, unless you did it intentionally for benchmark purposes or something.
3) No, having two won't slow things down.

[Kagthul]

Having too many devices attempting to access sata/pci-e lanes can most assuredly result in slowdowns or disabled devices. 2 won’t typically do it, but this post proves why most tech support is garbage.

Thats a pretty hot take, considering:

2) The only way you could slow down their performance is by having both of them transferring a great deal at the same time. Which.... won't happen, unless you did it intentionally for benchmark purposes or something.

Is saying exactly what you said.

Hot garbage, indeed. But not in the way you're intimating.

way to fail.

[WurstKaeseSzenario]

I have a 256GB M.2 SSD for Windows and the pagefile.sys, a 3TB HDD for storage, and a 1TB SATA SSD for games. Load times are no problem.

[chazus]

Having too many devices attempting to access sata/pci-e lanes can most assuredly result in slowdowns or disabled devices. 2 won’t typically do it, but this post proves why most tech support is garbage.

Im not even sure what you're implying with the last statement.

[Hypasonic]

Thanks all for the replies, think I'll just get another nvme then and see what happens!

[Shakadam]

Ofc they're routed via the chipset. The CPU cannot operate with any storage devices without the PCH. The only difference is that primary storage on AMD is not configurable, you always have those lanes dedicated to the M.2 slot. PCIe lanes just mean that there is a direct physical connection to the CPU, the operation is still controlled by the PCH. External controller are a bit more complicated but let's not get into that.

I'm sorry but this is just not true. A Zen CPU is a System-on-Chip. It can directly handle everything that's needed to run a system. The only reason motherboards have a chipset is to multiplex the x4 link from the CPU to create further connectivity, because having the Zen SoC handle everything that most people want to connect to a motherboard would take up more space on the die and make for complicated tracing.

For example, the x570 chipset is literally exactly the same chip as the I/O die in a Zen2 CPU. They have the exact same functionality. I think you need some kind of auxiliary security processor to make the CPU even boot, but you could design a motherboard completely without a chipset/PCH if you wanted to and have everything run from the CPU and its I/O die.
Not much benefit to doing things like that though so I'm not sure if there's anything available to buy which is configured like that, but something like the Asrock Deskmini A300 runs almost everything directly off the CPU.

This article on igorslab has some further reading about this:
https://www.igorslab.de/en/a-ryzen-w...oll-activator/

[Thunderball]

I'm sorry but this is just not true. A Zen CPU is a System-on-Chip. It can directly handle everything that's needed to run a system. The only reason motherboards have a chipset is to multiplex the x4 link from the CPU to create further connectivity, because having the Zen SoC handle everything that most people want to connect to a motherboard would take up more space on the die and make for complicated tracing.

For example, the x570 chipset is literally exactly the same chip as the I/O die in a Zen2 CPU. They have the exact same functionality. I think you need some kind of auxiliary security processor to make the CPU even boot, but you could design a motherboard completely without a chipset/PCH if you wanted to and have everything run from the CPU and its I/O die.
Not much benefit to doing things like that though so I'm not sure if there's anything available to buy which is configured like that, but something like the Asrock Deskmini A300 runs almost everything directly off the CPU.

This article on igorslab has some further reading about this:
https://www.igorslab.de/en/a-ryzen-w...oll-activator/

I'm aware how the platform is designed but notice the "ensure maximum compatibility" words. Every single desktop motherboard that's designed roughly from the middle of 2000s has a very specific launch sequence that make PCHs mandatory. Which is roughly: standby power > SMC init > operational power > PCH init > initialization of primary external devices, of which CPU is last. Point is: yea, I know Zen I/O die can operate some storage independently and in theory doesnt need a PCH but all desktop boards are designed in a way that this just wont work. This is very unlikely to change since it ensures that AMD/board partners control which CPUs are supported by each board, and we're not stuck with X370 forever.