WD Purple 3TB Surveillance Hard Disk Drive - 5400 RPM Class SATA 6Gb/s 64MB Cache 3.5 Inch WD30PURZ

Pros: The video surveillance market continues to grow and as cameras in increase in resolution, storage needs increase. Home and small business systems that involve up to a few dozen cameras and have the need to be cost efficient are the target for “Surveillance Specific” hard drives. The two main contenders are the WD Purple series (this) and the Seagate Surveillance series. They achieve “enterprise” disk levels of performance at a fraction of the cost as long as they are used in their very specific task niche.

What video security systems have in common is that they have to spend most of the time writing multiple data streams continuously (at relatively low data rates per stream) while spending only a minimal amount of time reading from disk. This drive supports 145 MB/sec sustained data transfer rates with a 6Gb/sec SATA interface. Your typical 1080p IP camera generates a H.264 or H.265 data stream well under 2 MB/sec. Surveillance drives are tuned to not lose frames when writing while their reading efficiency is mostly a secondary concern.

WD Purple drives market “AllFrame” technology which is a tuned system for writing up to 64 camera streams without losing data 24/7. Annualized workload is 180 TB/year. There is a 3 year warranty. 65 degree C max operating temperature. Low RPM (5400 class). LOW POWER USE.(4.4 W). WD assumes that you will be Reading back video 20% of the time. Their website is pretty amazing in helping decide what drive you need to buy based on: number and type of cameras, how many days of video you need to store, etc. You don’t have to do the calculations yourself. No RAFF limits you to 8 drives in a system. Corrosion resistant components start at 4 TB and above in this product line.

As a contrast, Seagate assume that Reading is only 5% of the workload, their website is not as directed toward the home/non-IT consumer but they have a “Safe and Smart Selection” white paper. 180 MB/s transfer rate. Up to 64 cameras. 3 year warranty. 70 degree C operating temp. 5.6 W. Faster RPM. No Rotational Vibration sensor till you get above 3 TB.

Advantages of the WD Purple over the Seagate at the 3 TB level is; 1) better website to select the drive you need; 2) lower power use; 3) if you will be reviewing video from your cameras fairly often WD assumes you will be doing this 20% of the time vs Seagate thinking you will do this 5% of the time. Read commands complete faster on the WD. Allframe technology streamlines performance based on a known workload.

For downsides of WD Purple vs. Seagate Surveillance see cons below.

Cons: Downsides of the Purple Drives: They are not intended for rack-mount systems since they suggest no more than 8 drives in a system and don’t have RAFF to reduce vibration effects from other drives in the same enclosure.

If you need 20-30 MB/s more data transfer rate at the 3TB size at the cost of more power consumption Seagate gets you that. It also gives you 5 degrees more heat tolerance.

Once you exceed the drive’s performance boundaries, less than ideal results occur more rapidly on the WD so it is important to purchase the right sized drive(s) - the website is quite good at showing what you need. Seagate is going after pure write intensive results at high RPM so it responds more predictably to overloading its rated capacity. Seagate Surveillance drives at 4 TB and higher have RV sensors and you can have more than 8 drives in an enclosure if you buy that size.

Overall Review: If you need less than 8 drives in your application, power consumption is important, you want to review video rather frequently, and know your system size and its read/write workload, WD Purple is the way to go.

If you want to do only a write-only workload and only read very occasionally, have a need beyond 8 drives at 4 TB and higher, and power consumption is not a factor - go with the Seagate.

If money is not a factor and you are a big enterprise using racks of drives, move up to the SAS interface enterprise drives from either vendor (at more 2-10 x the price). They will do everything these do and more, but then you already know this because you are an IT pro with an unlimited budget working for a big corp.

I tested this drive using several systems: i7 processor with Quick Sync Video capability on a Windows 11 system running Blue Iris software and connected to 15 IP POE cameras of varying resolution from various vendors using H.264 compression. Max res being 5 MP. Exacq professional system NVR in RAID5 config. Consumer grade, single disk system. Worked well, was compatible, and all advertised specs were met. Low power and low heat generation. Reading from the system while continuing to do writes worked quite well.

Pros: NONE

Cons: They sent me a DOA hard drive and when I returned it they refused to replace it.

Overall Review: AVOID