In this two-part blog series, we have a look at PCIe (PCI Express) SSDs, what they are, what products are currently available, and the performance benefits they can bring to your computer.
In part 1 I'll be discussing the relevance of PCIe SSD's to Windows / Linux systems and in part 2 I'll look at the benefits of this relatively new technology in relation to Apple Mac computers, with specific attention on the 2006-2012 model Mac Pro tower systems.
SSDs: from SATA to PCIe
'Traditional' SATA-based SSD's transfer data via the SATA bus of a computer and do so at rates that top out at a maximum of around 550-560MB/s for the higher performance models. It's widely accepted that this is the maximum level of sequential read/write performance achievable by a single physical SATA drive.
It was at CeBIT 2009 that OCZ Technology demonstrated a 1TB PCIe x8 based SSD that achieved a maximum read/write speed of 654/712MB/s respectively. The technology was very expensive, but for the first time the old SATA speed limits were surpassed by a product designed for use in a standard desktop computer.
What is a PCIe SSD?
PCIe-based SSD's differ from their SATA-based brethren in that they are designed to transfer data directly over the PCIe bus, which allows them to achieve sequential data transfer speeds exceeding 2000MB/s, depending on the number of PCIe lanes used.
These higher transfer speeds provide a similar kind of performance increase that traditional SATA SSD's offer over standard mechanical hard drives. This means faster boot-up times, faster application and game loading, and the ability to move large amounts of data very quickly.
Up until recently the usual form factor for a PCIe SSD was a card like the Mushkin Scorpion Deluxe model (pictured on the left in the image at the top of the page).
In late 2013 Samsung announced they had commenced manufacturing of a new kind of SSD based on the M.2 form factor - the XP941. Soon after, Sony announced the Vaio Pro 13 Ultrabook - which was the first windows-based laptop to use the new XP941 PCIe SSD. This had benchmarked data transfer speeds almost double those of the highest performing SATA SSD's.
A customised version of the XP941 was also deployed in the new models of the retina-screened MacBook Pro, MacBook Air and Mac Pro 'tube'. It has a custom edge connector which has so far prevented any third party from producing a compatible SSD upgrade product.
Current PCIe internal SSD product upgrade options for Windows / Linux desktops
Although there are a number of PCIe-to-SATA SSD adapter card products on the market, I'm just looking at the internal PCIe based SSD products that you can use to upgrade your computer with right now. This isn't an exhaustive list either, just the products that we carry in the RamCity store at the moment.
I consider the Plextor M6e the entry level PCIe SSD option which gives you better-than-SATA performance at a reasonable price. It's aimed squarely at gamers but is also a viable desktop or workstation upgrade read/write transfer speeds go up to 770/625MB per second so long as the product is installed in a PCIe 2.0 slot with at least 2 PCIe-lanes (x2).
The M6e is actually a combination M.2 SSD combined with an adapter card and sold as one product. It has a 5-year warranty and comes in 128GB, 256GB or 512GB capacities. It's bootable on Windows 7 or higher platforms and Linux. Although not officially supported on on Mac, several internet forum users have reported success installing this SSD in the Mac Pro under OSX.
Full Plextor M6e product details are here.
Mushkin Scorpion Deluxe
The Mushkin Scorpion Deluxe PCIe SSD range is currently the highest performing single slot, single card PCIe SSD product. It offers industry leading sequential transfer rates of 2160/1960MB/s read/write when the product is installed into a PCIe 2.0 x8 or higher slot. It's available in capacities in 480GB, 960GB, and 1920GB, and bootable in Windows / Linux, but not yet supported on Mac.
We do not sell Mushkin Scorpion Deluxe products yet.
The Samsung XP941 is a stand-alone M.2 format SSD, and although a diminutive 80mm long and 22mm wide, is currently the fastest performing PCIe SSD available in its respective 128/256/512GB capacities.
Originally, the only PC platform that the XP941 would boot in are select models of the Sony Vaio Pro 13 notebook. In recent months, ASrock have released their Z97 Extreme 6 (and new Extreme 9) motherboards with their custom 'Ultra M.2' socket which will run the XP941 at full speed on 4x PCIe lanes, and is fully bootable.
ASUS has also followed suit with boot support on their latest X97 based motherboards, albeit with an M.2 socket which is wired up to just 2 PCIe lanes. It can also be used as high speed storage in other desktop computers when combined with an adapter card, but is not bootable. You can read more about the M.2 standard in this blog post.
Full product and compatibility details of the Samsung XP941 are here.
Our personal thank you to Rod who wrote this excellent tutorial