Just noticed in my original post that I wrote it was a WD40EFRX disk failing, but it was a WD30EFRX in my case but it shouldn’t make any difference, just different size. That's a welcome announcement for users who want to make the decision of when, and where, to use SMR drives in their systems and NAS arrays.

All Red Labeled Western Digital are top products for storage/NAS/SAN purposes and this drive is no exception. The thing i'm pointing out is the characteristics of the EFAX and EFRX seem to be very different - at least in a in a QNAP NAS and you probably shouldnt mix them if you can avoid it.is from the same family and all the fields from the found table row are valid for it, meaning model WD60EFRX-68L0BN1(6TB) and WD40EFRX-00L0BN0(4TB) are from the same family. Turns out while both are offered as RED drives the EFRX is native Western Digital, EFAX is a drive technology acquired as part of Western Digital integration of Hitachi Global Storage and built in a different factory and probably has many other differences than just cache. They are built to withstand a lot of wear and tear, making them a good choice for long-term storage. Western Digital’s exclusive NASware™ technology fine tunes drive parameters to match NAS system workloads which helps increase performance and reliability. If it's true that the newer 6 TB WD Red are also HGST inside, then obviously that specific low power technology isn't the best.

Now i noticed that a new WD Red Plus line has entered the market in 2021, namely the EFZX series with 128mb cache instead of 64mb cache currently used by the EFRX series. The table above lists the WD drives that come with SMR technology and the drives that use the faster conventional magnetic recording (CMR). To find out more about how to support this advice service check HERE If you need to fix or configure a NAS, check Fiver Have you thought about helping others with your knowledge?As I said to the OP earlier, make a warranty claim pointing out that the performance is unacceptable compared to the previous version. They are mainly bought for being NAS compatible, not using a lot of power, running cool, running silent and being relatively low cost. inch form factor ensures easy integration into desktop setups, delivering reliable performance, ample storage space, and seamless compatibility.

The backup drive has been around for about 2 years, but has spent most of it's life sitting on a shelf. Note that the width of the access time graph is about 8ms which is the max rotational latency of a 7200 RPM drive. technology increases your drives’ compatibility with your existing network and devices, TV, stereo, and more. We’ve partnered with Ontrack to provide protection for routine and extreme data loss scenarios such as drive failure, viruses, and software issues. Synology even lists this disk as a SMR drive and mentions Due to the characteristics of SMR, this SMR drive might have longer response time than a PMR drive.As WD Red is the only 5400 rpm disk on the market it isn't the best choice if high performance is expected to begin with. For those googling for the answer whether combining WD EFRX and WDEFZX (WD40EFRX and WD40EFZX in my case) would be safe. I understand that you're disappointed but now that you don't recommend using WD60EFAX, what's the better alternative for replacement when WD60EFRX are unavailable? I assume that you use some kind of RAID and while the WD60EFAX will slow your RAID down, it's still the gigabit networking that's the bottleneck in your TS-451+ so you shouldn't be noticing any performance difference from your client devices.