NVMe SSD on a Pentium II?

Added: 2026-05-14

[00:00:00]Hi guys, Omar here. So, what do you think? Is it possible to use an M.2 NVMe SSD on a Pentium 2 PC? I know it sounds like one of those trick questions you may get asked in a Google job interview or something like that.

[00:00:16]Now, the Pentium 2 came out in 1997. PCI Express hit the market around 2004, and NVMe SSDs came along about 10 years after that. So, using an NVMe SSD on a 1997 board doesn't sound like something that should be even possible.

[00:00:35]But, if you understand how PCI Express works, it starts to look actually doable, at least in theory.

[00:00:43]So, why are we even talking about a PCI Express since a Pentium 2 motherboard has classic PCI slots and definitely no M.2 slots? Well, M.2 NVMe drives are nothing more than standard PCIe devices.

[00:00:59]They just use a different physical connector. That means any NVMe drive can be plugged into an M.2 to PCI Express adapter, which does nothing fancy. It simply maps the M.2 pins to their PCI Express slot equivalents. And the reverse is true, too. You can pull a PCI Express slot out of an M.2 slot if you need to go the other way.

[00:01:26]All right, I guess you already know where I'm going with this. Yes, PCI Express devices can be plugged into a PCI slot.

[00:01:34]All we need is a PCI to PCI Express adapter, one that uses a bridge chip like the PEX 8112.

[00:01:43]What that chip does is act as a translator in both directions. It tells the NVMe SSD that is running on a PCIe X1 connection. And at the same time, it tells the BIOS that is dealing with a irregular PCI device. The bridge chip doesn't actually need to do much heavy lifting here because a PCI Express was specifically designed to be software compatible with the original PCI architecture. This means that even an older BIOS can still detect the PCI device, allocate the resources for it, and hand it off to the operating system just like it would with an any normal PCI card. That's exactly how I managed to install a GTX 980 on a Pentium 3 system. So, in the same way our NVMe drive should end up looking like just another device on the PCI bus. And once we get to that point, everything comes down to having the right drivers for it.

[00:02:44]But before we get into drivers, there are two more things that can get in the way. First, there is the PCI slot itself. Only PCI slots only provided 5 volts, while later PCI revisions also added a 3.3 volt rail.

[00:03:00]This usually isn't a big deal since many PCI cards are universal and can run in either 5 or 3.3 volt slots. However, for our M.2 NVMe setup, 3.3 volts really matters because this is the standard operating voltage for M.2 NVMe SSDs.

[00:03:21]So, if the 3.3 volt rail is missing on the actual PCI slot, the adapter can't do anything about it, and the NVMe drive won't power up. The good news is that this Intel 440BX motherboard does provide 3.3 volts for the PCI slots, so we're good to continue. But, for example, this Socket 7 motherboard with a VIA MVP 3 chipset doesn't provide a 3.3 volts on its PCI slots. So, on this board our PCI to PCIe setup simply won't work unless we're willing to do some modding.

[00:03:57]The second thing that can cause problems is the BIOS. The NVMe drive is running behind an extra PCI to PCI bridge, which is technically perfectly valid. The PCI specification actually allows up to 256 bridges, but some early BIOSes don't handle this very well, and either won't scan beyond the first PCI to PCI bridge or won't allocate PCI resources correctly. So, let's see how this goes.

[00:04:29]Now, except some early drives like the Samsung 950 Pro, NVMe SSDs don't include a legacy option ROM for BIOS boot support. Instead, they rely on the motherboard firmware to contain an NVMe driver and initialize the drive during boot. And obviously, that's not the case with a Pentium 2 motherboard.

[00:04:50]Or really any motherboard released before the NVMe standard existed.

[00:04:55]One interesting workaround for older systems is to load an NVMe capable boot loader through a network card's PXE option ROM.

[00:05:05]This is something very useful, so I'll cover that in a future dedicated video.

[00:05:12]But for now, let's boot from a SATA drive and see if we can get Windows 98 to recognize the NVMe SSD.

[00:05:19]Why Windows 98? Well, that's what most people had on their Pentium 2 PC. I know I did.

[00:05:27]And if NVMe and Windows 98 sounds like an impossible relationship, well, it is not because as of late 2025, we actually do have a brand new NVMe driver that works with Windows 2000 NT, and it was ported to Windows 98 as well.

[00:05:48]The original Windows 2000 and NT version was made by Dominic Beer, while the Windows 98 port was done by Sweetlow. Both of versions are easy to install and actually pretty reliable.

[00:06:01]Now, since the NVMe driver was already installed on my Windows 98 SSD, at the first boot, the NVMe driver was picked up right away and the driver asked for a restart. But, a driver can install and still not work. I've seen that plenty of times before. So, the moment of truth was basically one restart away.

[00:06:25]And guess what? So, now we have a functional NVMe SSD in Windows 98, which is nothing really new here on the channel, except this time we are running it through the classic PCI bus.

[00:06:37]Uh so, I guess it's time to celebrate this with another song. I know you liked it last time. Uh this time I'm recording through a Creative Sound Blaster 16.

[00:06:48]And honestly, that's one of the main reasons you would want a Pentium 2 system in [music] the first place, because it still has ISA slots. Wait for the lyrics and then we'll check the transfer speeds.

[00:07:01]>> [music] [music] [music] [music] >> Pentium time, 97 [music] board, but I'm feeling fine. Dropping NVMe in a PCI line. Bridge chip talking like, "Yeah, that's mine." [clears throat] Old BIOS looking at [music] me confused. 3.3 volts and the drive gets juiced. Windows 98 like, "What's this thing?" Driver kicks in, boom. NOW IT'S SINGING. YOU CAN'T run this, >> [music] >> but we run this.

[00:07:41]NVMe on a Pentium 2. We done this.

[00:07:44]>> [music] >> You can't run this.

[00:07:46]The mix is sick and the crowd goes nuts with it.

[00:07:53]>> [music] >> PCI bus All right, and now let's check some of our transfer speeds. Unlike a PCI Express, where we have a plenty of bandwidth on the PCI bus, the total bandwidth is just 133 MB per second.

[00:08:12]And that bandwidth is shared between all devices on the bus, not per device. In practice, usable transfer speeds are actually a bit lower because of PCI bus overhead and protocol encoding. So, in CrystalDiskMark, we get around 100 MB per second read speeds.

[00:08:32]The bandwidth is directly tied to the PCI bus frequency, which normally runs at 33 MHz. So, if we overclock the system and PCI bus goes up to around 36 or 37 MHz, transfer speeds already increase to around 110 to 115 MB per second.

[00:08:55]And if you remember that earlier video where I tested the same NVMe drive with the same PCI to PCIe adapter on an PCIe X1 slot, I got around 200 MB per second because there the bridge chip was running at 66 MHz.

[00:09:14]So, what can I say? Compared to a classic IDE drive from the Pentium 2 era, an NVMe drive is in a completely different league, as it should be. But in practice, software meant for Windows 98 will still load fast enough even from a regular IDE hard drive.

[00:09:33]One thing to keep in mind, though, is that this NVMe setup can run at 66 MHz?

[00:09:39]So, it should remain very stable even if the PCI bus gets overclocked.

[00:09:46]Next, I ran the same tests in Windows NT.

[00:09:51]Over a PCIe connection, this a Samsung NVMe drive can hit about 1.4 GB/s.

[00:09:58]Seeing these kinds of numbers on a 996 operating system is not bad at all, even if they are still below what a typical Gen 3 NVMe drive can deliver.

[00:10:10]Of course, the NT NVMe driver will also work over the PCI bus, but the results are basically the same as in Windows 98, around 100 MB/s at stock PCI speeds, and about 110 with some overclocking.

[00:10:26]All right, so we can definitely call this a success.

[00:10:31]And honestly, I don't think this is just a because we can type of thing.

[00:10:35]I mean, you may already have a retired NVMe SSD lying around, and if you want the fastest low-power storage for a classic PCI system, this whole setup is still way cheaper than going with a compact flash card, which to be fair behaves like a regular IDE drive, so it's more compatible, but the cards themselves aren't exactly cheap, and you still need an adapter.

[00:11:02]And speaking of adapters, someone has already taken this NVMe on a PCI idea much further.

[00:11:09]I'm talking about the NL from SDC Mods, who recently came up with this crazy thing, a PCI X to NVMe adapter that also works on the regular PCI bus.

[00:11:21]On PCI X, you can get up to 1 GB/s of bandwidth, and this adapter got pretty close, reaching around 800 MB/s on an SGI O2 system.

[00:11:32]I really hope I can get my hands on this Xbridge card soon.

[00:11:37]Although I don't actually have any PCI access systems right now.

[00:11:41]Anyway, hope you enjoyed this video and if you made it this far, please check if you are subscribed to my channel.

[00:11:48]YouTube tells me around 9% of my viewers are not and I feel like I should probably do something about that. I don't know. Amiga res out.