Quick Answers
CMR (conventional magnetic recording) hard drives have been the standard hard drive technology for many years. They offer a good balance of performance, capacity, and affordability for most users.
The main benefits of CMR hard drives are:
- Proven and reliable technology
- Good value for money in terms of storage capacity per dollar
- Reasonable performance for everyday tasks and gaming
- Wide availability from many manufacturers
The downsides are that CMR drives are slower than modern SSDs for booting, loading, and multitasking. They also have higher failure rates than SSDs over time. However, they are still a very popular choice for systems and external storage where large capacity is needed at a reasonable price point.
What is a CMR Hard Drive?
CMR stands for “conventional magnetic recording” and refers to the traditional hard drive design that has been used for decades. A CMR hard drive stores data on spinning magnetic platters which are read from and written to by a moving read/write head.
The technology works by magnetizing small regions on the platters to represent 1s and 0s of digital data. The read/write head floats just above the quickly spinning disk, allowing it to access data from any location.
Hard drives using conventional perpendicular magnetic recording have been the dominant form of storage in desktop PCs, laptops, game consoles, and consumer NAS devices for many years. While solid state drives are taking over the market for high performance systems, CMR HDDs continue to offer a compelling value proposition for cheap and plentiful storage.
Advantages of CMR Hard Drives
- Low cost per gigabyte – CMR drives provide a lot of storage capacity for the price
- High capacity options available – Up to 16TB for 3.5″ CMR drives
- Proven and mature technology that is reliable
- Good performance for non-critical tasks
- Wide availability of drives from major manufacturers
Disadvantages of CMR Hard Drives
- Slower than SSDs for boot, app/game loading, and multitasking
- Higher failure rates than SSDs in the long run
- More prone to damage from drops/shocks when used in portable devices
- Produce more noise, heat, and vibration compared to SSDs
- Not ideal for mission critical 24/7 operation in servers/NAS
CMR vs SMR Hard Drives
The main alternative to CMR hard drive design is SMR – shingled magnetic recording. SMR squeezes more data onto platters by overlapping the magnetic regions a bit. This allows for greater drive capacities but with some performance drawbacks.
Here’s a quick comparison between CMR and SMR hard drives:
| CMR | SMR | |
|---|---|---|
| Capacity | Typically lower density | Higher density platters |
| Performance | Faster sequential speeds | Slower write speeds |
| Price | Slightly higher cost per TB | Lower cost per TB |
| Ideal workloads | Faster access from anywhere on disk | Sequential, not random access |
In summary, CMR drives are a better choice if you want reliably fast performance for gaming and everyday computing. But SMR drives allow you to get more storage capacity for your money.
Performance of CMR Hard Drives
The performance profile of a CMR hard drive can vary substantially depending on factors like:
- Rotation speed (5400 RPM, 7200 RPM, 10,000+ RPM)
- Cache size (64MB vs 256MB)
- Form factor (2.5″ laptop drive vs 3.5″ desktop drive)
- Interface (SATA 3Gbps, SATA 6Gbps, SAS)
However, in general CMR hard drives offer quite decent performance for everyday tasks, gaming, and media usage. The table below shows some average performance numbers for a typical 3.5″ 7200 RPM CMR drive using a SATA 6Gbps interface:
| Metric | Performance |
|---|---|
| Sequential Read Speed | Up to 200 MB/s |
| Sequential Write Speed | Up to 180 MB/s |
| Random Read IOPS | Up to 100 IOPS |
| Random Write IOPS | Up to 130 IOPS |
These speeds allow for reasonably fast booting, game loading, and media playback. Of course, SSDs are 3-5x faster in many usage scenarios, but CMR drives are still quite responsive for many tasks.
Factors Affecting CMR Hard Drive Performance
There are a few key factors that determine the speed of a CMR hard drive:
- RPM – Faster spinning drives (10,000 RPM) have higher transfer rates but use more power.
- Cache size – Larger caches (64MB+) improve buffering and burst speeds.
- Areal density – More densely packed platters mean faster access to data.
- Interface – Newer SATA and SAS offer 6Gbps maximum throughput.
In general, high performance enterprise drives spin at 10,000-15,000 RPM, have large caches, and SAS interfaces. But for home builds, a 7200 RPM SATA drive with 64MB cache provides the best balance of speed, price, noise, and reliability.
Reliability of CMR Drives
CMR hard disk drives have proven to be quite reliable over many years of consumer usage. However, they do have a higher failure rate than solid state drives over time.
Most CMR drives used in desktops and laptops are designed for a lifespan around 3-5 years or more of 24/7 usage. Their mean time between failures (MTBF) is typically rated between 500,000 to 1 million hours.
This makes them suitable for primary storage. But for mission critical data, backups and redundancy are still a good idea.
For frequently accessed data, SSDs are around 2-3x more reliable than hard drives based on field usage studies. But CMR HDDs are perfectly reliable for less frequently accessed data like media files, documents, etc.
Tips to Improve Reliability of CMR Hard Drives
- Handle drives gently and use anti-shock mounts in portable devices.
- Keep drives cool with adequate airflow.
- Avoid excessive vibration which can damage drives over time.
- Perform regular backups to protect against data loss.
- Use enterprise class drives rated for 24/7 operation if needed.
- Use RAID to protect against drive failure.
Noise Levels
Due to their mechanical moving parts, CMR hard drives produce more noise compared to silent solid state drives. However, noise output has reduced over the years with improved designs.
For a modern 7200 RPM 3.5″ CMR HDD, the typical noise level is around 20-30 dBA when idle or under typical workloads. This is a relatively quiet humming sound that is unlikely to be distracting.
However, faster 10,000+ RPM drives and smaller form factors like 2.5″ laptop drives tend to have louder noise outputs in the 30-40 dBA range. This may be audible in very quiet environments.
Using sound dampening materials, anti-vibration mounts, and large quiet cases can further reduce noise levels. But ultimately, solid state drives with no moving parts are the quietest option.
Power Consumption
CMR hard drives need to spin up platter motors and power active read/write heads. This results in higher power draw compared to SSDs. However, power usage has been declining with modern drive designs.
A typical 3.5″ CMR hard drive has an idle power consumption of 5-10W. Under heavy access load, power usage can spike up to 10-15W.
Laptop hard drives use less power, often under 5W even under load. For comparison, SSDs use just 2-4W for most models.
CMR hard drives go into low power modes when inactive to help save energy. But ultimately SSDs consume less power over time, especially when accessing frequently.
Capacity Options
One of the main benefits of CMR hard drives is the very high capacities available at reasonable costs. Currently typical CMR HDD capacities include:
- 2.5″ laptop drives – Up to 5TB
- 3.5″ desktop drives – Up to 16TB
- Enterprise 3.5″ drives – Up to 18TB
These large drive sizes are ideal for storing media libraries, backups, and large files at a low cost per gigabyte. SSD capacities top out at around 16TB for high end models currently.
Hard drive capacities continue to grow steadily by around 35% per year. 20TB CMR hard drives are likely to be available for desktop use within a couple of years.
Price Per TB Comparison With SSDs
Due to their mechanical design, CMR hard drives continue to offer far lower price per terabyte than SSDs. Typical current pricing is around:
- 2TB CMR HDD – $50, $0.025 per GB
- 2TB SATA SSD – $150, $0.075 per GB
As a rule of thumb, CMR hard drives tend to cost 3-4x less per TB than SATA SSDs for most capacity points. This makes them very compelling for bulk storage needs where maximum speed is not required.
Ideal Usage Scenarios
CMR hard disk drives work very well in these scenarios:
- Gaming PCs – CMR HDDs provide ample space for large game installs at low cost. Use a smaller SSD for active games.
- Desktop storage – Great for storing media, documents, backups, etc.
- External storage – Portable USB CMR HDDs add terabytes of storage for cheap.
- NAS/Servers – Reliable SATA CMR drives are popular for bulk storage in RAID.
- Laptop mass storage – Better value than small SSDs for the money.
For primary OS and application storage, SSDs are highly recommended. But CMR HDDs still play an important secondary storage role in many systems.
Alternatives to CMR Hard Drives
The main alternatives to CMR hard disk drives are:
- SSDs – Much faster and more reliable, but at a higher cost per gigabyte.
- SMR HDDs – Denser platters for lower cost, but slower write speeds.
- Hybrid drives – Combine a small SSD cache with a HDD platter.
- Cloud storage – No local storage, but access data from the internet.
- NAS – Centralize storage on a network attached appliance.
Each have their own pros and cons. But for most home and office users, a combination of one or more SSDs and CMR HDDs provide the ideal blend of speed, capacity, and affordability.
Conclusion
CMR hard disk drives continue to offer exceptional value for money when large amounts of storage is needed. The technology is proven and reliable after decades of refinement.
While solid state drives are faster, CMR HDDs are more than adequate for gaming, media storage, backups, and other secondary storage needs. Their high capacities and low cost per terabyte make them easy to recommend where SSD-level speed is not required.
Reliability is improved by handling drives gently, mounting them securely, keeping them cool, and using redundancy like RAID. But even without special precautions, modern CMR hard drives are dependable workhorses for most home and office tasks.
Overall, CMR hard drives combine great capacity and good real world performance with affordability. This versatility ensures they will continue to have an important role in systems that need massive secondary storage. For many users, a combination of SSDs and CMR HDDs is the ideal storage configuration at a reasonable price point.
