PCI Express or PCIe, is a computer motherboard expansion ports or interconnects. It stands for Peripheral Component Interconnect Express. Its used to expand the performance, functionality or connectivity in server or similar systems. NICs, graphic accelerator cards, RAM expansion modules, etc. are common examples of devices that are connected through PCIe slots. While they are here for performance improvements in the system, Solid-State Drive in form of NAND flash are newer technology for PCIe. While it is fastest way anything can be connected to the system, there are certain functionality that we need to give up. We will discuss about the PCIe SSD pros and cons in this particular article.
SSDs are in popularity because speed is what we need. If we can match the operational speed with the processing speed of the CPU, there will be absolutely no lag in the system. Moving closest to the system, PCIe provides the max speed of communication between the processor and the storage media. While hard drive rotational speed didn’t increase in decades, moving to the faster alternative is what introduced SSD, mSATA SSD, m.2 SSD and nor PCIe SSD. The PCIe SSD pros and cons are discussed in the sub-topics below.
PCIe SSD Pros
PCIe 3.0, the latest one supports the transfer speed of up to 985MB/s per lane. PCIe devices can support 1x, 2x, 4x, 8x or 16x lanes meaning the transfer speed up to 15.76GB/s. Though you will not find any consumer grade SSD with that many lanes. You will find something with 2x or 4x data lanes. So, the max transfer speed will be up to 3.94GB/s.
PCIe is bidirectional that means it can read and write simultaneously. So, it eliminates protocol translation of SAS, SATA or FC storage. Being able to write and read simultaneously makes it faster than external devices.
The installation process is fairly simple, easiest to install and use as well. External systems, especially those one with storage network and shared host are complex to implement. PCIe SSD just needs to be plugged to the PCIe slot, that’s it.
- Closest to processor
Flash on a PCIe car puts the SSD closest to the CPU memory within the server and affords a lower potential latency. It is closest to the CPU memory. Many overhead processes are not needed like communicating with the controllers to read and write to and from the system.
Further Reading: mSATA SSD Pros and Cons
PCIe SSD Cons
The per GB cost of PCIe SSD is much expensive than the normal SATA SSD. The amount you will be paying for the PCIe express is the highest in the hierarchy. Its for obvious reason that things higher up in the hierarchy are definitely faster and costlier.
- Costs 1 PCIe slot
If you are planning on shifting to the PCIe SSD, you are giving up most precious PCIe slot just for the sake of the speed. PCIe slot is for expansion and often is used with graphics cards, NICs and many more. Giving it up for storage option might not be that feasible.
- Power consumption
If you are doing normal task that are CPU or RAM intensive, then there won’t be any difference in consumption, but when you are constantly reading and transferring data, PCIe SSDs will use more energy and drain battery quickly.
It is an internal, bus-connected device. PCIe SSD will cause you to reboot every time you install or replace making the maintenance job disruptive. Meaning maintenance job will make your system unavailable for precious amount of time.
- No sharing
It can be counted as pro or con depending on the situation. Being a dedicate not storage but treated as memory by the DMA, PCIe SSD can’t be shared with other servers. You can count it as the additional layer of security, or just a plain disadvantage.
The PCIe SSD pros and cons are not so much different from the ones of 2.5-inch SSD, because at the end they both are SSD. The limited PE cycle holds true for this as well. All the cons of SSD are still present, but the biggest pros is its speed and ability to bidirectionally read/write simultaneously. Depending on the pros and cons of PCIe SSD, though it is expensive, you can decide whether to switch to it or not. you can buy some of the PCIe SSD from Amazon as well at reasonable price.