By the time you read this, the initial Intel X99 motherboard and Haswell-E processor reviews should be online. Before X99, a small number of products supported the M.2 interface, and even less support the PCIe x4 option. With X99 that changes, nearly all of the X99 motherboards we've laid eyes on support PCIe x4.
The M.2 form factor supports both SATA and PCIe SSDs, but only PCIe based SSDs take advantage of the extended performance range over SATA III. At this time, there are only two products available on the market that meet both criteria, M.2 and PCIe. Those products are the Plextor M6e, a PCIe 2.0 x2 SSD and the Samsung XP941, a PCIe 2.0 x4 SSD.
The fastest product of the two is the Samsung XP941 and that's the model you want. The Plextor M6e is a nice product and you can buy it with a M.2 to PCIe adapter in the box, but since both cost about the same, your money is better spent on the Samsung drive.
Early on, using the Samsung XP941 required some hoops to jump through to get it to boot. Those issues revolved around using the device on older chipset motherboards that didn't take full advantage of UEFI. Nearly all of the big name motherboard manufacturers have updated BIOS information and it's now possible to get XP941 to boot on most Z87 and Z97 motherboards. X99 should be the first chipset to have zero issues as the norm.
Specifications, Pricing and Availability
Today, we're looking at the Samsung XP941 256GB, one of three capacity sizes offered by Samsung. We've already tested the 512GB and the 128GB models, all provided to us by RamCity.
The XP941 256GB has a sequential read speed of 1080 MB/s and a sequential write speed of 800 MB/s. This is a significant step up from the performance of the 128GB model, but just a bit shy of the large 512GB XP941 model. Random performance on the XP941 256GB comes out to 120,000 read and 60,000 write.
To get that level of performance, Samsung tapped a new 3-core controller and paired it with Low Power DDR2 DRAM and 19nm Toggle MLC NAND flash. The UAX controller is a PCIe to SATA bridge that operates on PCIe 2.0 in either x2 or x4 mode. To get the most out of your XP941, you need to use an x4 slot, but using an x2 (10Gb/s) slot will only reduce the sequential read by 80 MB/s and have little or no effect on the sequential write speed.
RamCity has all three capacity sizes in stock and ready to ship. Customers outside of Australia don't pay the Australian taxes. Without the tax, the prices come out to $129 (128GB), $249 (256GB) and $488 (512GB). Today, we're looking at the 256GB model at $249. The price falls into my 'less than 300 per component' sweet spot. It's still close to $1 per GB and around $49 more than an 850 Pro 256GB. That said, the XP941 256GB is faster than the 850 Pro, and surpasses the limits of SATA III.
The XP941 products from RamCity ship with a three year warranty.