Dual M.2 M-Key NVMe Ports to PCIe 3.0 x16 Bifurcation Riser Controller - Support Non-Bifurcation Motherboard (SI-PEX40129)

I purchased two of these boards. Each board has the option for two M.2 drives. They provide amazing performance on my older i7 board which only has PCIe 2.0a support. My previous M.2 board did not have the onboard chip which is apparently a PCIe lane "switch" which basically allows more use of the slot bus. The M.2 cards I installed are PCIe 3.0 x4 cards so on my old card this would translate to PCIe 2.0 x4 since the motherboard did not support PCIe 3.0. Due to the fact that each PCIe 3.0 "lane" is twice the speed of a PCIe 2.0 lane I would not get half the performance. The onboard "switch" processor allows use of more lanes and allows near PCIe 3.0 performance. Keep in mind that having two M.2's on one card mean they still share the slot bandwidth. Windows does not support booting from software created striped volumes and the cards don't have a RAID chip on them to create hardware RAID. Actually, I wish this card did support hardware RAID such as striped volumes, it would be a great feature. What I did is purchase two cards and placed four M.2's on them. I placed my C drive on one (Windows). Then I placed a smaller cheaper M.2 on the second card as extra storage because due to the PCIe "lane switching" placing only one M.2 on the card will cause lockups and system freezes. In slot two on both cards I place high speed 1TB M.2's and created a striped volume. Placing them on separate cards allow them to utilize separate "switch" processors to ensure maximum performance. Then I reinstalled Windows and interrupted the installation to set the Users and Program folders to my striped volume. Then on my first login, I moved the page file to my striped volume. Now I have maximum performance out of my two M.2's with a total 2 TB on the striped volume. Thus far the setup works great HDD access is amazingly fast and probably faster than anything the creators of this motherboard expected. Also, I created a large 50-100 GB swap file because the drive is really fast so paging does not provide a noticeable slow down and effectively gives me all the memory space I need. I typically just leave everything open and running allowing me to quickly return to things. Overall, if you are looking for the maximum performance out of your PCIe 3.0 M.2's this is THE card for you. Pros: - On a PCIe 2.0 system this is likely the fastest way to add an M.2 HDD - Allows extreme performance even on a PCIe 3.0 slot. - PCIe lane Switch processor allows nearly full use of the slot - M.2 Cooling features like thermal pads heat spreader and fan. - Allows two (or more) M.2's in one slot (a lot of other cheaper cards have one M.2 one slot) Cons: - Does not have hardware RAID, I realize this may require a different processor, but it is a big feature. - Requires both M.2 slots to be populated due the PCIe lane switching. - While the SATA hard drive interface comes on the motherboard this requires the purchase of a 200 dollar card.

Incidible value if you can find m.2 SSDs for cheap. Useful to add fast storage in the bottom pcie slot of your motherboard if you need it and have the extra pcie lanes. Careful with adding a 5th drive however, especially if you do a redundant raid configuration. All five drives under load will slow the whole array down due lane constraints. It works best in a storage pool without redundancy.

Installed in 2009 Mac Pro tower with 2 AData 512GB NVMe SSDs, planning to use one for Mac OS and the other for Windows 10 Pro. Initially worked great as speedy non-boot drives. Attempts to use as a Bootcamp drive for Windows 10 completed install but would not boot. As a Mac OS 10.13.16 High Sierra boot disk it would boot with significant delay, resulting in a slower boot time than my Sata SSD. Occasionally the system would refuse to boot. I'd have to use the startup option key and force boot from the Sata SSD. After 2 months, the drives disappeared from the desktop and then the machine would not boot if the card was installed. I separately tested the SSDs and they were fine. I am assuming it is broken - a waste of money.

I bought this for a Mid-2012 Mac Pro which has 4 PCIe 2.0 ports, two of them 16x. This card works great in slot # 2, which is a single wide slot. Slot 1 in the Mac is double wide, but that's occupied by an AMD Radeon RX 580. Which means that this card blocks slot 3, only leaving one additional slow available. Also, the NVMe blades get very hot and after a bit, I noticed "artifacts" on the screen that weren't there before and didn't re-appear after the card was removed. Black Magic's SSD benchmark shows this card with 2 Samsung 2TB (4TB in total) achieve write speeds of up to 2450 MB/sec and read speeds of up to 2895 MB/sec, which is great for an old machine with PCIe 2.0. The card is, however, designed for PCIe 3.0 where it should be twice as fast and maybe not have the artifacts on the screen either. In real-life performance tests, the internal SATA-2 drives that have direct slots on the Mac's motherboard worked better and produced a more linear performance. I mostly use those drives for Virtual machines and where a VM would boot up in 20 seconds on the SATA-2 drives (in a 3-drive RAID0 configuration) it would boot up anywhere between 60 and 180 seconds on this controller. I do not blame the controller for this issue, it might very well be the older PCIe back plane combined with insufficient power. Unfortunately, I had to return the card and the blades.

I recently went about doing a storage upgrade to my desktop, a fairly old machine that predates the popularity of NVMe. (Though support was given for PCIe adapters in a BIOS update.) Originally, I'd opted for an Asus Hyper adapter, but quickly found out I was unable to use it with more than one NVMe drive due to my motherboard not supporting lane bifurcation. (I have one drive for Windows and one for Linux, so I want to be able to use both.) This product seems to be the cheapest product on Amazon that will work with motherboards that don't do PCIe lane bifurcation. (Bifurcation is the act of splitting up one x16 PCIe interface into multiple smaller interfaces, in this case allowing multiple NVMe drives to use the same PCIe interface.) That being said, this product is obviously not cheap as far as price. I'd like to compare the Asus Hyper to this card on a few points: The Asus Hyper (that I got) cost $69 (Nice.) while the IOCrest cost $200. The Asus was super well built and felt very premium. The IOCrest is shoddy and feels like a product I'd buy for cheap on eBay from China. The fan on the Asus was barely audible. The fan on the IOCrest, while not loud, has the same tone as a server power supply, which is not a nice sound. But again, it's not loud thank god. The Asus supports four NVMe drives. The IOCrest supports two. The Asus (that I got) supports PCIe 4, the IOCrest only supports PCIe 3. The Asus requires the motherboard to support lane bifurcation, the IOCrest handles that itself That last point is important, don't get me wrong. It's the sole reason I'm using this over the Asus Hyper. And it is super important to note that the chip needed to make this work and support circuitry adds significant cost to manufacture, but I kind of doubt that pricing scales well. Especially with the corners that seem to have been cut. And I'd really like to drive home the quality issues that you get with this $200 device. Quality issues that actually render the device completely useless without taking some stupid measures. Honestly... I can live with the not so premium feel of the product. But it's the screws that really screw you. Look, both the box and the product have a QC (quality control) sticker on them, but I am SURE this is bunk. Most of the screws came pre-stripped with one so bad that I was completely unable to remove it. This renders the device useless as I could not put my NVMe drives in. In order to remedy this I had to use a file to file a slot into the screw and use a flathead screwdriver to get it undone. This process took me the better part of an hour. Once inside, I was able to install everything as needed. The NVMe's didn't go into place nearly as nicely as on the Asus Hyper, but it was still totally acceptable. One of the screws for the fan was straight up missing. Like it was just never put into place. But not all is lost, because it seems IOCrest is painfully aware of the atrocious screws used in this product... because they supply you with extras. I kid you not. They seem to know that you're going to need extras because they give you three extra screws. I was thus able to replace the one I had to file AND install the fan screw that they just didn't install. So conclusions: You're paying $200 for this product, but the quality is that of some $10 electronic you'd buy off eBay. I can live without it feeling premium like the Asus Hyper, I can even live with it feeling a bit cheap. But the screw situation NEEDS to be addressed by IOCrest if they want this product to be at all acceptable. And for that, I really can't recommend this. But at the same time, if you're in a situation like me where your motherboard doesn't support lane bifurcation but does support PCIe NVMe and you want to utilize multiple NVMe's on one PCIe interface... well, you're options are limited and the price only goes way up from here.

This review is for the 2 slot version of the card with the ASMedia PCIe switch chip. I bought this in hopes of getting full NVMe performance on a Mac Pro 5,1. What I found is that the performance of this supposedly x16 card is identical to an x8 card, B07PRN2QCV Ableconn PEXM2-130 Dual PCIe NVMe M.2 SSDs Carrier Adapter Card - PCI Express 3.0 x8 Card Support 2X M.2 NGFF PCIe NVMe SSD for Mac & PC (ASMedia ASM2824 Switch) - Support Non-Bifurcation Motherboard . That meant I was getting around 2,500 MBps on a single SSD, and combined around 4,000-4,500 MBps on two at once. Pretty good, but less than what the SSDs can actually do on a true PCIe gen 3 bus. Based on this card being advertised as, and physically looking like, an x16 card I was expecting to see more along the lines of 3,000-3,500 MBps for one SSD and 6,000-7,000 MBps on both simultaneously. Nope. And I did confirm that both of the NVMe drives were capable of > 3,000 MBps in a different machine that has PCIe gen 3. When I pulled the card out and looked closer, what I noticed is that the PCB only has traces from half of the PCIe connectors. The other half of the PCIe connectors go nowhere. In other words the card is physically x16, but is actually only x8 electrically. That sounds reversed, but since only half of the PCIe electrical connections are routed anywhere on the board that is what it is. It does work, just not as expected or advertised. The heat sink is quite solid and has thermal interface material pre-applied in the appropriate locations with a protective sheet covering the material. I didn't use the heat sink for my testing since the Ableconn card I was testing it against didn't have a heat sink either. I debated between 3 or 4 stars for the overall rating. I opted for 3 because I specifically wanted this card because it was listed as PCIe x16, and it physically is a PCIe x16 card, but it turned out to only be PCIe x8. The intended use, and what the description led me to expect, was being able to do PCIe x16 gen 2 from the Mac Pro -> ASMedia PCIe chip -> 2x PCIe x4 gen 3 NVMe drives. What it actually offers is a PCIe x16 physical connection -> PCIe x8 electrical connection (gen 2) -> ASMedia PCIe chip -> 2x PCIe x4 gen 3 NVMe drives. Yes, it works, but the overall performance available is cut in half and can be achieved with a different card, at less cost, and without requiring a physical x16 slot. One other interesting tidbit for the Mac Pro owners. The System Information report does see the card (the two individual NVMe slots actually), but it reports the connections as 8.0 GTs (PCIe gen 3) rather than 5.0 GTs (PCIe gen 2, what the Mac Pro actually is). I wasn't expecting that, so I assume that it is reporting back the information returned by the ASMedia chip which is gen 3 facing the NVMe slots. Personally I'll be returning this card and sticking with the Ableconn since the performance is identical, it is less expensive, and the smaller size is more flexible for use in other systems. I might try one of the 4-slot NVMe cards at some point in the future since those are true x16 cards just to see if those will give the expected 6,000-7,000 MBps for 2 (or more) active drives in the Mac Pro. Side notes for other MacPro 4,1/5,1 owners: - Yes, it is bootable on a Mac Pro, you just have to go through the necessary firmware upgrade steps for it to work. First is the firmware update prior to High Sierra (10.13) that gives APFS boot support, then the firmware update prior to Mojave (10.14) that gives NVMe boot support. - You can actually use it with Sierra (10.12) but Sierra only works with NVMe drives operating in 4kn mode (4k sectors). Most drives come in 512e (512 byte sector emulation) mode for compatibility, but Sabrent offers a tool (Sabrent SSC) to switch their drives between 512e and 4kn operating modes. - Sabrent SSC actually shows all NVMe drives, not just Sabrent ones. Since I had a Toshiba XG5 (not recommended!) that I was removing, I thought I would try the tool on it to see if it worked. If it bricked the drive it wasn't a major loss for me since I was removing it anyway. I tried using the tool on it, rebooted the system (required after switching the operating mode), and confirmed that the drive reported it was in 4kn mode. In other words, if you are like me and avoiding upgrading past Sierra, and happen to have access to Windows, it may be possible to switch other NVMe drives to 4kn mode to use with Sierra. Your mileage may vary, and note that switching the operating mode will completely erase the drive. Update: Changed from 3 to 4 stars because it does work. I still think the advertising text should be updated so that it doesn't describe it as an x16 card since it isn't one.

I purchased the card to get the maximum performance out of a Samsung 970 Pro NVME on a classic Mac Pro. Normally, an NVME blade installed in a classic Mac Pro slot can only reach 1500MB/sec due to the gen 2 PCIe slots that the cMP has. With this card installed in a 16x slot, it can combine 8x gen 2 to create 4x gen 3 speeds. With a blade on this card, I could reach over 2900MB/Sec from the same 970 Pro. Problem is, with only one blade installed, it will hang and then restart the Mac when copying large files. I could have purchased another SSD, but knowing that the card is flakey with just one led me to return the card... I just couldn't trust it. They also included the wrong screw sizes for the NVME standoffs.

I installed a 500 GB m2 nvme blade drive in this and put it in a Mac Pro 4,5/5,1 (a pci-e v2 slot). Hight sierra did not see it...at all. Not there. Went thru the hassle to update to Mojave and it still did not see it, let alone offer it as a boot drive. A freaking waste of money is what it is right now, And it kinda makes me mad. EDIT: The problem was mine. The MP4.1 has a rod that secures the back notch on long cards. I didn't realize this and thought it was seated...but I was wrong. Pulled it out and moved it into an x16 slot (where I have been running a Kingston Predator AHCI blade drive—which I moved to an X4 slot) and put this guy in. Took some fussing, but when rebooted, the drive popped right up. Cloned the new Mojave installation to it and rebooted. Wonderful The Amorphous Diskmark program shows it about 20-25% faster than the Kingston which is about 10X faster than the stock Sata 2 ports. I used a Silicon Power nvme drive, not wanting to risk the price of the faster Samsung. But this carrier holds two...<G>