Pros: As usual, shipping time from newegg.com was expeditious and the hard drives (quantity of 2) arrived undamaged and very well packaged. Once I opened the shipping box, the inside revealed air cushion fillers and 2 WD-branded cardboard boxes. Each WD cardboard box contained a Hard Drive in a shock absorbing cradle. I was very happy with the shipping.
- WD Red NAS hard drives are recommended by the manufacturer for use in home and small office NAS systems with 8 or less Hard Drives.
- I have had 2 of these 4TB Hard Drives installed in my Seagate STDD4000100 NAS Pro 2-Bay Network Storage (Newegg items N82E16822178609 and 9SIA2W02VG7768). I removed 2 of my old hard drives from my NAS and I have replaced them with two new hard drives (each is 4 TBs). I then went through “diskless” setup of my Seagate NAS, which took about 20 minutes. The NAS needed to download new firmware and the hard drives were reformatted and I set them up in JBOD set up. The formatted capacity showing by my NAS was 7.9 TB.
- After prolonged use and multiple large data transfers, the NAS reports Hard Drive temperatures of 41 and 42 degrees Celsius. I transferred large amount of data in multiple folders (about 40 gigabytes worth) back and forth between my rMBP and my NAS using wireless AC connection. Much to my surprise, large data transfers did not raise temperature of my hard drives.
- NASware 3.0 is preinstalled.
- 3-year limited warranty is pretty generous.
- Interface speed: SATA 6 Gb/s.
- Internal transfer rate/speed up to 150 MB/s. In real life I was clocking sustained transfer rates of about 108 to 117 MB/s over gigabit ethernet (desktop PC) and ac wireless (rMBP).
- Drives seem quiet.

Cons: - When I tried to register these drives with WD for warranty purposes, I received “out warranty” status for both drives, even though they were manufactured in January of 2016. I opened “service case” with WD customer service and they were very quick to update warranty information for my drives. My new warranty expiration date is March of 2019.
- I suggest you keep your receipts, check your serial numbers and make sure your warranty information is correctly recorded by the manufacturer.

Other Thoughts: - I was very pleased with the drives through out my testing. The installation process was painless, the drives are quiet and did not run hot in my NAS. The transfer rates are good. The drives are designed for prolonged use in NAS setup. The warranty is generous. WD brand is well known and price is competitive for the quality they offer. I have used these drives for about 3 weeks in my NAS. I have encountered no problems. Right now, I trust these drives with my personal data.
- If you need spacious drives for your NAS, you can’t go wrong with the WD WD40EFRX drives.

Pros: WD Red drives are pretty solid and reliable for long term storage and always-on NAS devices. I've used 3TB REDs previously, and recently dropped two of these 4TB drives into my custom built NAS. In a RAID 1 configuration I was able to get consistent read speed of 130MB/s and some peak speeds around 150MB/s.

Being 5400RPM, these drives are a little quieter than some of the other similarly rated 4TB NAS drives, and they use less power at peak load as well. I didn't notice any major temperature issues with these drives inside of a Node 304 or in my Seagate NAS enclosure even when under full load writing to disk.

Cons: Compared to faster 7200RPM NAS drives I have running on my network, these 4TB drives were the bottleneck in my media server (Only for testing purposes, they went into long-term storage after the tests). I tested real-time BDMV streaming and TV tuner writing to disk from several media devices on the network and noticed some performance issues when in RAID 1, an issue I don't normally have with my 7200RPM disks in the same configuration.

Other Thoughts: The power savings are a nice to have, but these drives are not meant for anything taxing like this and are better off used as a file-server for shared home directories or central file repositories. If you're looking for hosting media for streaming on a NAS I'd definitely shoot for 7200rpm drives instead. For something I'm trusting to hold all of my data in a central location, having only a 3 year warranty is a bit of a let down, but that's the route that consumer drives go these days.

Pros: Both of the hard drives worked perfect out of the box. It was tested in a seagate 2 bay NAS that I had received for a review last year. The drives went in no problem and I set up a raid 1.

I could list all the speeds but when doing something like this the hard drive is not the determining factor in those speeds it is the hardware that is supporting those hard drives so the numbers would be altogether useless information.

The drives ran slightly above room temp (1c) which is great for long term viability in my opinion.

The drives are quiet, I can barley hear them operate which is also a plus in my book if it is going to be in something that is going to be on 24/7.

Overall these drives performed as one would expect them to and I had no issues with them.

Cons: None that I'm aware of. If one were to die or run into issues I would probably update with another review.

Other Thoughts: These are great server / nas drives and the only real advantage I see with these over green drives is that they were designed to be operated in RAID arrays and on 24/7 without hybrid sleep states which cause all sorts of problems with raid arrays.

The 3 year warranty is nice although i still remember when 3 was typical and 5 was the nas / upper level drive warranty terms

Pros: I installed 2 of these drives into a Seagate STDD100 NAS Pro 2-Bay, and set them up in a RAID 1 array with no problems at all. At 5400RPM they very quiet and will run cooler than a faster drive, but that will ensure better longevity.

Speed and performance tests are great, but no two systems or networks will be exactly alike in the scheme of things. Everyone will always come up with something different for read/write speeds. And depending on the type of NAS box you use, RAID setup times will vary from system to system. On my network I do run automatic software for system backups overnight. Depending on the size of individual file transfers I always use an FTP program, which is much faster than drag/drop or copy/paste!

These drives are designed to take a beating as far as reading and writing data goes. And Western Digital has a great color coded system for their drives that is based by the type of environment, and the specific needs you have for data storage. Very cost effective if you have large amounts of data you need to backup, and they come with a full 3 year warranty.

In essence RAID is a method of using multiple drives to create one faster and/or more reliable drive. The different RAID levels differ in the way they store data which affects usable space, performance and reliability. What they all have in common is they use multiple hard drives and create a single virtual 'RAID' drive, which can be used like it was a single disk.

Cons: None!

Other Thoughts: I have been purchasing hard drives for many years on Newegg and have never received a drive that was DOA. The same goes with many friends and family members who purchased hard drives upon my recommendation from Newegg.

These two drives were shipped from the west coast to the east coast, and they worked flawlessly upon arrival and passed all of my specific tests!

Pros: - Cost per GB is something I never thought I would see on a WD Red.
- Available up to 6TB
- Newest version of NASWare should improve reliability
- 3yr warranty is great for the price for use in NAS
- Spins cool and quiet
- Mounted and installed fine on older model seagate NAS

Cons: - None so far.

Other Thoughts: I had an older Seagate 2bay NAS (STBN100) left over from a previous review so when offered two of these 4TB bad boys to test I jumped at the offer to see how they would perform in an older NAS box from a competing brand to see what would happen!

After installing the two 4TB drives I booted up the NAS and the drives were showing up as blank and ready to "clean and install" according to the Seagate software. However after trying this and a Processing... message for about 10 minutes the drives came back as "foreign".

So I logged out and back in of the web panel to try again and still got the "foreign" message, as a last ditch effort I restarted the NAS and on the 3rd time the drives processed fine and everything worked as intended. So I am to assume the old Volume was still loaded into the NAS OS in some form and wasn't installing properly.

Once I had the drives mounted and ready I created a RAID 1 volume which took approximately 12.5 hours to build at a rate of 70-72MB/Sec and I was left with a perfectly working RAID 1 volume.

Then I performed a few tests reading and writing to the drive with my Macbook Pro and the three Win 10 machines I had in the house. I was able to achieve 38-42MB/Sec write speed to the NAS wether I was writing to it with one machine or all 4 simultaneously. My read speeds were 68-72MB/Sec to all machines on my gigabit and wireless 802.11 AC network.

I was very impressed by the performance and cost per GB on these drives for the current cost of this drive the 3 yr warranty cost roughly $50 a year for peace of mind to know your drives are covered should anything happen even though Western Digital is known for having a good product with their RED line of drives, if your looking to fill up a NAS box look for further than these products for your home or office NAS.

Pros: How much of the "RED" for NAS storage is just marketing is anyone's guess, but I've only had great experiences with WD Red drives in my NAS bays and these 4TB drives are no exception.

I placed 2 of these into my Seagate NAS Pro 2-Bay to upgrade the 4TB to a total of 8TB. The 4TB WD Reds are every bit as quiet as the other 2TB Red drives even though they have more platters. That is probably the biggest benefit of the Reds over 7200RPM drives, they run cooler and quieter than performance drives, which leads to longer lifespan and still providing good performance levels in SOHO NAS units.

The standard RED drives have a shorter warranty period than the "Pro" Red drives, 3 year vs. 5 year, so if you have really important data you may want to spend on the pricier drives. Personally, I use RAID5 on my 4-bay NAS and if a drive fails, I replace it instead of paying for a better warranty up front. So far so good, none of my NAS Red drives have failed, although some of my repurposed 1TB drives have.

Anyways, enough rambling, on to the performance numbers!

These 4TB Reds in RAID1 performed extremely well, I was getting 125MB/s transfers on the Seagate NAS Pro with these WD Red 4TB drives compared to 110MB/s on the Seagate included NAS drives. So a slight bump up there. For most NAS units, you will probably not notice the difference as you will be limited by the transfer speed of the NAS.

I'm really enjoying not having any mechanical drives in any of my PCs or client desktops anymore. Just local SSD storage and everything else goes to my NAS units in a closet and in the basement.

The drives were packed exceptionally well by Newegg. WD provides a cardboard box with molded HDD holders for the drive itself, and Newegg double-boxed these with air packet cushions. Both drives worked perfectly as expected.

Cons: None really, obviously price increases exponentially with every drive/bay you add to your home NAS, so if you are running a 4-bay or 6-bay NAS it can get expensive at $600 or $900 in hard drives!

But! That's the price we pay to keep our data intact!

Pros: + Overall decent desktop PC peak performance of around 157MB/s.

+ In a NAS RAID-0 (striped) configuration, two drives are able saturate the 1Gb network connection for the whole 8TB of read/write. So a peak performance can be expected of around 120MB/s.

+ Very slightly less power consumption than an equivalent competitor’s 4TB NAS hard drives. Power consumption is even more impressive on the 6TB versions of Western Digital Red hard drives when comparing to others on the market.

Cons: - With it being a typical platter drive, the drive’s speed is not consistent across the whole 4TBs. At the start, the drive achieves 157MB/s, but at the 4TB mark is down to 70MB/s.

- When doing a NAS RAID-1 (mirroring) configuration, the drives will become a bottleneck on a Gigabit network connection.

- The Western Digital Red 4TB hard drives are not quite as fast as competitor’s 4TB NAS hard drives.

- 64MB Cache provided vs. 128MB offered on competitors’ drives.

- Only a 3 year warranty is provided

Other Thoughts: The performance of these drives is more or less in line with other drives in the NAS category. When used in such environment, in a RAID array, they should provide very good performance where the network connection will become the limiting factor (i.e. bottleneck).

These drives are shipped with no instructions, cable, nor installation hardware. Also, if purchasing a number of drives for a NAS environment, it may be advisable to purchase an extra drive to have as spare. The spare drive will have the same firmware, therefore limiting any compatibility issues and downtime at a later date when a drive within the NAS ends up failing.

Pros: There isn’t a whole lot I can say about the Western Digital Red 4TB NAS Desktop Hard Disk Drive Model WD40EFRX-68WT0N0. A hard drive either works or it doesn't. I received two of these and installed in a NAS storage enclosure for testing. The mirroring setup was quick and painless. My read/write speeds have been comparable to the other disks I previously had installed in the NAS enclosure. I will be keeping them under moderate to low I/O usage and powered on 24/7. I believe time is going to be the deciding factor for the drive quality. These drives do run noticeably cooler and quieter than the WD Black drives I replaced.

Cons: None as/of yet.

Other Thoughts: Will report back if I run into any issues.

Pros: Incredibly fast drive.
3 year warranty.

Here are the benchmarks for the 2 disks I was asked to evaluate:
Disk 1:
-----------------------------------------------------------------------
CrystalDiskMark 5.0.2 x64 (C) 2007-2015 hiyohiyo
Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

Sequential Read (Q= 32,T=10) : 219.077 MB/s
Sequential Write (Q= 32,T=10) : 273.186 MB/s
Random Read 4KiB (Q= 32,T=10) : 2.338 MB/s [ 570.8 IOPS]
Random Write 4KiB (Q= 32,T=10) : 1.983 MB/s [ 484.1 IOPS]
Sequential Read (T= 1) : 157.068 MB/s
Sequential Write (T= 1) : 149.951 MB/s
Random Read 4KiB (Q= 1,T= 1) : 0.593 MB/s [ 144.8 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 1.815 MB/s [ 443.1 IOPS]

Test : 500 MiB [E: 0.1% (4.9/3725.9 GiB)] (x3) [Interval=5 sec]
Date : 2016/02/21 15:33:37
OS : Windows 7 Professional SP1 [6.1 Build 7601] (x64)

Disk 2:
Sequential Read (Q= 32,T=10) : 221.953 MB/s
Sequential Write (Q= 32,T=10) : 313.066 MB/s
Random Read 4KiB (Q= 32,T=10) : 2.316 MB/s [ 565.4 IOPS]
Random Write 4KiB (Q= 32,T=10) : 1.955 MB/s [ 477.3 IOPS]
Sequential Read (T= 1) : 167.979 MB/s
Sequential Write (T= 1) : 153.719 MB/s
Random Read 4KiB (Q= 1,T= 1) : 0.591 MB/s [ 144.3 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 1.677 MB/s [ 409.4 IOPS]

And just for comparison, here are results of the same test on a Seagate ST4000VN000 4tb NAS disk which will cost you the same money here at Newegg:

Sequential Read (Q= 32,T=10) : 199.938 MB/s
Sequential Write (Q= 32,T=10) : 119.424 MB/s
Random Read 4KiB (Q= 32,T=10) : 1.575 MB/s [ 384.5 IOPS]
Random Write 4KiB (Q= 32,T=10) : 1.611 MB/s [ 393.3 IOPS]
Sequential Read (T= 1) : 155.183 MB/s
Sequential Write (T= 1) : 154.790 MB/s
Random Read 4KiB (Q= 1,T= 1) : 0.551 MB/s [ 134.5 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 1.572 MB/s [ 383.8 IOPS]

Cons: I can't find anything wrong with these drives. I beat the heck out of them for 3 days straight and experienced no issues. Obviously, only time will tell how reliable they will be, but that's the case with any hard drive. At only $40/TB, RAID is your best friend.

Other Thoughts: One of the big problems with hard drives is that they can be fine today and dead tomorrow. Fortunately, since this is a NAS drive, it is very likely that anyone purchasing it will be configuring it in a RAID 1, 5, 10, etc.. array and a single hard drive failure will not result in data loss. If you are configuring your NAS as JBOD or RAID 0 and care about your data, then you need to have your head examined. Hard drives are way too cheap to risk your data like that.

Given all of the bad reviews on these drives, I tried to focus on endurance tests. I started by putting each one (I was given 2 to evaluate) into my PC. I performed a low level format on each drive, then ran Western Digital's Data LifeGuard Diagnostics Extended test on both of them. These tasks took several days to complete, and no errors were reported. I then ran bench tests on the disks (see Pros).

Once I finished beating these up in my PC, I popped one into my 2-bay Seagate NAS Pro (STDD8000100), broke the mirror and resync'd it with this WD disk. I tested the NAS and it worked fine. I then removed the WD disk and replaced it with the other one, resync'd it again, and it again everything worked fine. Both the WD and Seagate 4tb NAS disks were running the same temperature (+/- 2 degrees) throughout all NAS activities.

For anyone who still doesn't get that disks are advertised with their raw (unformatted) capacity, please be aware that formatted, this disk is 3725.9 GB. Also, note that some older NAS boxes (or computers, for that matter) might not recognize 4TB disks. If you have an old one, you might want to do a little research before buying these, or any other large disks.

Pros: These drives are built for NAS performance and I anticipate that they will contiinue to do so. Quiet and run relatively cool. WD builds great drives and the 3year year warranty make me confident of my RAID.

Cons: None if you buy them on sale, I had to wait a bit for the 4TB to become reasonably priced but for for my 32 Tbyte RAID it was well worth it

Other Thoughts: Highly recommended!