When I was choosing the hard drives for my DIY NAS NVR system, I did a ton of research. I wanted to record all my IP cameras 24/7, so reliability and performance were very important to me.
In this article, I will share all my findings so that you have all the information you need to make the right choice.
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Seagate IronWolf vs. WD RED – Comparison Table
| Feature | IronWolf (12-18 TB) | IronWolf (4-10 TB) | WD RED (2-6 TB) |
|---|---|---|---|
| 24/7 operation | ✓ | ||
| RAID support | All configurations | ||
| Recording technology | CMR | SMR | |
| Enclosure | 1-8 bays | ||
| Drive design | Helium | Air | |
| Performance | |||
| Spindle speed | 7200 rpm | 5400/5900/7200 rpm | ~5400 rpm |
| Cache | 256 MB | 64 / 256 MB | 256 MB |
| Max sustained data transfer rate | 210 - 240 MB/s | 180 - 210 MB/s | 180 MB/s |
| Reliability | |||
| Power-on hours per year (24x7) | 8760 | Not available | |
| Workload | 180 TB/year | ||
| MTBF | 1 million hours | ||
| Load/unload cycles | 600,000 | 600,000 | |
| Non-recoverable Read Errors per Bits | <1 in 10^15 | <1 in 10^14 / <1 in 10^15 | <1 in 10^14 |
| Vibration sensor (RV) | ✓ | ✕ | |
| Data Recovery | 3 years (Seagate Rescue Data Revovery) | ✕ | |
| Power Management & Noise | |||
| Average power consumption | 7.3 - 7.8 W | 4.8 - 10.1 W | 4.1 - 4.8 W |
| Idle power consumption | 5.0 - 5.5 W | 3.4 - 7.8 W | 2.3 - 3.1 W |
| Standby power consumption | 1.0 - 1.2 W | 0.25 - 1 W | 0.4 - 0.6 W |
| Noise levels | 28-30 dB | 23 - 32 dB | 21 - 27 dB |
| Warranty | 1M hours MTBF 3-year limited warranty | 3 years limited warranty | |
| Price | |||
Seagate IronWolf vs. WD RED – The biggest difference
The biggest difference you ought to be aware of is the recording technology used. CMR is widely recognised as the superior technology whereas SMR is a newer slightly inferior tech that especially suffers from poor random write speed.
Let’s start with Western Digital. A few years ago all WD drives used to be CMR. This was also how WD described their drives in their marketing material. But in early 2020, several users started complaining about unusually lengthy RAID building times or outright failures on adding their brand new WD RED drives to an existing RAID array (also called re-silvering).
When pressed, WD admitted that they had switched some of their drive models from CMR to SMR without notice. WD even settled a class action suit related to this matter and promised better communication. As part of the settlement, WD admitted that the SMR based RED drives are not suitable for NAS and RAID usage.
What about Seagate and even Toshiba? Well they too have admitted selling SMR drives without disclosing it.
The whole controversy had one positive effect – WD is required to disclose the recording technology used in their drives for 4 years whereas Seagate is doing so in their marketing material and datasheets.
So where does that leave us today? Unfortunately, the WD Red drives are now all SMR. If you want CMR, you need to step up to the WD Red Plus model range. While some users may be able to make do with the SMR-based WD RED drives, I suggest you give them a miss.
Thus in this comparison, Seagate IronWolf drives which are all CMR-based come out ahead.
Performance
Comparing real-life benchmarks of the IronWolf 4TB vs. WD RED 4TB, overall the IronWolf is much faster.
Independent testing by other publications such as Hardware.info have also shown that the IronWolf drives are much faster than the WD RED drives.
However because of the fact that WD and Seagate have been selling SMR based drives without disclosing it, past benchmarks may not be the best indicator. Since CMR based drives have overall better performance than SMR drives (the datasheets confirm this too), Seagate IronWolf drives win here.
Reliability
While we may not have specific reliability data for the IronWolf and RED drives, one cloud storage provider regularly publishes drive failure data for all the drives it uses – Backblaze.
Looking at the latest Backblaze data, in general the WD drives appear to have less reliability than Seagate. But at lower capacities, Seagate seems to be much worse. So a real mixed bag. Although do note the sample size is much larger in Seagate’s case for most drive sizes, generally the higher the sample size, the more accurate the data becomes.
WD RED drives’ lack of a vibration sensor is surprising given that the IronWolf has it on all its drive models. Also worth noting is that the WD RED’s Nonrecoverable Read Errors Rate of 1 in 10^14 is worse than that of the IronWolf’s 1 in 10^15.
So let’s call it a tie when it comes to reliability.
Noise levels
The IronWolf runs at higher RPMs compared to the WD RED, so its no surprise that the IronWolf is also louder on average than the WD RED drives.
I have been using WD RED drives in my QNAP TS-253A and can confirm that these drives are super quiet. I have my NAS in my living room, inside the TV unit and can barely hear the drives when they are active.
The VueVille Verdict
Drive technology – Seagate IronWolf wins thanks to CMR recording technology instead of the inferior SMR.
Performance – Seagate IronWolf wins.
Reliability – Tie.
Noise – WD Red wins.
Overall, the Seagate IronWolf wins.
So which one did I choose?
I wanted to run a RAID 1 setup so that all my data would be backed up on 2 disk drives – for this reason I was not after absolute speed and the WD RED drives were available at a better price point. Also note that this was before WD started selling SMR drives without disclosing the change from CMR. So I am very happy with my old CMR-based WD REDs.
However, knowing that the WD RED drives are SMR based, I cannot in good conscience recommend them. Either go for IronWolf or the WD Red Plus range which are both CMR based. When its time to change drives, I will be using only CMR based drives like these.
Are these basic WD Red (SMR) drives, or Red Plus (CMR)?
Basic RED drives>8TB & all RED PRO drives use CMR.
Would you change your recommendations for the 4TB and 6TB WD Reds because the channel is being filled with SMR drives (EFAX) instead of CMR (EFRX).
SMR drives for NAS workloads (even consumer workloads) is not proven yet, end users and their data should wait for vendors to get the technology right for the use-case.
Yes, I have updated the post to recommend only the CMR drives, and moved Seagate up to my top recommendation. SMR drives have pathetically slow re-silvering times vs CMR drives.
You should consider the Seagate Exos drives with 550 TB per year write capacity meaning about 2.5 petabytes during the warranty period. Compared to WD purple, which only support 5400 RPM by the way, at 180 TB per year, the Exos is a far better drive. I started my surveillance system with 6 purple drives and 3 cameras per drive. All six purple drives failed within the warranty period. I’ve switched to all Exos drives and am hoping for a far better result.