The Seagate IronWolf Pro and Seagate Exos HDD lines represent the pinnacle of NAS drive performance. Both drive lines are designed to withstand the intensive I/O requirements of modern data-heavy business models, and they each have incredibly rapid spin speeds and expansive data capacities. There are, however, a few key differences between these two drive lines from Seagate, and we'll explore these relevant differentials in detail.


The IronWolf Pro line is the high-end spectrum of Seagate's IronWolf line. The entry-level options within the IronWolf line are suitable for home networking and even home computing purposes at the low range, and they are reasonably suitable for the demands of a small business NAS on the high range. To make their IronWolf line optimized for small and medium business applications, however, Seagate added special features to their IronWolf Pro line.

For instance, IronWolf Pro drives that have storage capacities of 10TB and up utilize cutting-edge helium filling technology. If you've ever held a balloon, you know that helium is less dense than air, and this low-density gaseous environment facilitates optimum drive performance. Drives that are filled with helium run faster, cooler, and quieter than drives that are filled with normal air, which means that they can be built to have higher capacities.

Since the Exos line is a step up from the IronWolf Pro line, it only makes sense that these drives are similarly filled with helium. Unlike the IronWolf Pro line , however, in which only some of the drives are helium-filled, every drive in the Exos line is filled with helium.

The Exos line is split into two subgroups, and each drive group has different attributes. The Exos X10 line, for instance, has drive capacities of 8TB and 10TB while the Exos X12 line features a 12TB and a 14TB drive. The Exos X12 line has a Sustained Data Rate (SDR) of up to 261Mb/s, but Exos X10 drives only have an SDR of 254MB/s. Furthermore, while the Exos X10 line is optimized for both hyperscale and traditional data center applications, the Exos X12 is designed specifically for hyperscale applications.

Hyperscale computing technology is seen as the wave of the future, and all of the major cloud providers now incorporate hyperscale distributed infrastructure into their data delivery architecture. While optimization for hyperscale computing may not be required for anything besides top-tier enterprise-level applications, investing in Exos X12 drives is a sure way to insulate your NAS array against obsolescence.

Major Differences

Before we touch on the differences between these drive lines , it's important to point out that both the IronWolf Pro and Exos lines offer five-year warranties. However, there are quite a few pertinent differences between these HDD lines:

  • Workload optimization: Also known as multi-user optimization, workload optimization is the amount of data that a drive is rated to handle per year. The drives in the Exos line are equipped to handle up to 550TB of reading and writing per year, but the IronWolf Pro series is only rated for 300TB per year.
  • Data rescue services: Seagate offers a data recovery service. If your drive fails within the warrantied period, they will do their best to recover the data on that drive. While IronWolf Pro drives come equipped with data recovery protection by default, data recovery is optional for the drives in the Exos series.
  • Mean Time Between Failures (MTBF): This metric measures the average time it takes a drive to fail. The MTBF for the IronWolf Pro series is 1.2 million hours, and the MTBF for the Exos line is 2.5 million hours.
  • Bay support: If you invest in IronWolf Pro drives, you can use up to 24 of these drives in a single NAS unit. The maximum bay support for the Exos series, on the other hand, is unlimited.
  • NAS optimization technology: Seagate equips their drives with firmware that allows them to operate fluidly within NAS systems. The IronWolf Pro series is equipped with AgileArray technology, but the Exos series features the updated enterprise-optimized framework.
  • RAID Optimization: Since the IronWolf Pro series is only capable of working with 24 other drives, the Exos series is more suited for RAID applications. However, as long as you don’t exceed 24 drives in your RAID setup, either drive type would be suitable.
  • Manufacturing Differences: While the drives in the IronWolf Pro series and the Exos series both feature eight platters and 16 heads, they use different types of recording heads. They both use perpendicular magnetic recording platters, but the newest Exos drives have two-dimensional magnetic recording (TDMR) heads that provide rapid read performance on thin platters. The drives in the IronWolf Pro series, on the other hand, use shingled magnetic recording (SMR) heads, which are not as effective or efficient as the new TDMR heads.
  • Cache Types: The IronWolf Pro series uses write-back caching policy, which is an outdated and inefficient form of caching. The Exos series, on the other hand, uses write-through policy, which is more efficient and which makes sure that the cache line always remains clean. Therefore, the Exos series is able to read and write data at greater speeds than the IronWolf Pro series while also helping to maintain drive health.

Ideal Applications

The decision of which drive to use will ultimately be determined by the intended application of each drive series. The IronWolf series was designed to be a crossover HDD that could be used either in home or business settings. This line debuted with the original IronWolf drives, which aren't really suited for any other applications than home or small business use. With the release of the IronWolf Pro series, however, the IronWolf family took a leap forward into the medium-sized business arena.

Since the IronWolf Pro series is still limited by its 24-bay maximum compatibility, it isn't really suited for enterprise applications. However, this HDD line's top-of-the-line spin speed and capacity makes it ideally suited for business applications with more than 50 but less than 500 employees. While you could conceivably use an IronWolf Pro drive for a home server, these drives are somewhat overpowered for such an application.

While even the IronWolf Pro line has certain limitations, Seagate designed the Exos series to be beyond limits. With a maximum storage capacity of 14TB and unlimited bay compatibility, the Exos series can be used in even the largest NAS systems. Exos drives are also slightly more responsive than IronWolf Pro drives in terms of I/O MB/s, and they are designed to tolerate intensive data loads.

The drives in the Exos series essentially represent the apex of Seagate's lineup, and they are suitable for any enterprise applications. However, Exos drives would be overkill for small NAS setups in small or medium businesses. Enterprise-level businesses can also absorb the costs associated with equipping Exos drives better than smaller companies.

Pros and Cons

Seagate IronWolf Pro


  • Adaptability: While the drives in the IronWolf Pro range may be beyond the price range of the average consumer, they are well within the reach of the amateur data enthusiast, and they represent the perfect options for small or medium business NAS applications.
  • Data recovery: When you buy one or more IronWolf Pro drive(s), you won't need to worry about investing in additional data recovery services.
  • Drive health: IronWolf Pro drives come pre-equipped with a drive health application that automatically pinpoints and resolves potential drive issues before they become serious problems.


• Limited applications: If you feel like your business might experience significant growth before your drives fail, you might want to steer clear of the IronWolf Pro series. Since these drives are only compatible with a maximum of 24 bays, you'll need to invest in a new NAS system if you want to expand beyond that hard cap.

Seagate Exos X10 and X12


  • Unlimited potential: Since the Exos series is compatible with any number of drives, the number of Exos drives you can combine in a single NAS is only limited by the number of bays in your server.
  • State-of-the-art responsiveness: Exos drives are some of the fastest on the market, and they are also designed to be highly durable.


  • Cost: The only real downside of the Exos series is that top-notch drives demand top-notch prices. However, the value that the drives in the Exos series provide balances out the cost.


By Editorial Team 6 comment


comments (6)

  • David Cole

    The Ironwolf and Ironwolf Pro drives use CMR, not SMR.

  • JF

    The information on Ironwolf Pro seems incorrect. As far as I know, Seagate does NOT use Shingled Magnetic Recording heads on the Ironwolf Pro line, or ANY of their Ironwolf line.

  • dave

    > The drives in the IronWolf Pro series, on the other hand, use shingled magnetic recording (SMR) heads

    This is just plain wrong, though I accept the information might have been hard to find..

    > The IronWolf Pro series uses write-back caching policy, which is an outdated and inefficient form of caching

    This one line destroyed the thin veneer of credibility you had managed to scrape together.

    Yes, the EXOS has “WCD” or Write-Cache-Disable set by default, but this is for data integrity, and will reduce performance. However as part of a large NAS, this is insignificant.

  • Paul

    you are claiming the Iron Wolf Pro is using SMR?

    Just the heads, or the actual recording scheme??

  • Someone

    Ironwolf pro does not use SMR!

Leave a comment

Your email address will not be published. Required fields are marked *

Please note, comments must be approved before they are published

Just added to your wishlist:
My Wishlist
You've just added this product to the cart:
Go to cart page