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Western Digital Caviar Black and RE4 2TB Drives Review
Date: Dec 09, 2009
Author: Joel Durham
Introduction and Specifications

It happens to all of us at some point. We constantly run short of hard drive space, no matter how incredibly cavernous you thought your current drive was when you bought it. Did you really expect Dragon Age: Origins and Borderlands to soak up almost thirty gigabytes between them? Didn't think so. You either shove Office 2007 and Photoshop CS aside to make some room for your latest losslessly-ripped music and RAW photos, or grab a drive that offers up more capacity, say up to 2TB--such as the ones we're going to be evaluating here.

You know the contenders. These aren't solid state drives full of a speedy but thimble-sized flash memory chips--these are large, succulent drives with platters humming at 7200rpm and they're made by Western Digital.

Taken to task today we have three drives in total: the Seagate Barracuda 1.5TB which we'll use as a reference point, and two relatively new offerings from WD: The RE4 2TB drive and the Caviar Black 2TB. Which of the three drives outperformed the others? There was a clear winner, and that particular drive is an absolute speed demon.

WD RE4 and Caviar Black 2TB Hard Drives

WD Caviar Black and RE4 2TB Hard Drives
Specifications and Features


Seagate Barracuda 1.5TB

Western Digital RE4 2TB

Western Digital Caviar Black 2TB





Host Interface

SATA 3Gbps

SATA 3Gbps

SATA 3Gbps





Form Factor

Standard half-height 3.5" internal hard drive




1.59 lbs

1.66 lbs

1.66 lbs





Average Latency

4.16 ms

4.2 ms

4.2 ms

Random Read Seek

<8.5 ms



Random Write Seek

<10.0 ms



Western Digital's spec sheets didn't specify seek times, but we'll figure them out via benchmarks. Looking at the specs, we can see that besides the difference in capacity, the most glaring difference between the WD drives and the Seagate drive is the cache. Will a double-sized cache make the WD drives perform better? We aim to find out.

WD 2TB Hard Drives

More Than Just Spinning Platters

Both of the Western Digital drives are brimming with interesting technologies. Besides their enormous capacities, each drive boasts dual processors; huge, 64MB caches; dual stage actuators; and more.


You've heard of multiple processors. Multi-CPU systems have been around for decades, culminating in the multi-core-single-die CPUs in today's mainstream computers; multiple-GPU graphics cards were common in the days of 3dfx (hell, that was before graphics card processors were even described by the moniker "GPU"). These drives, the WD RE4 and Caviar Black hard drives feature a pair of processors onboard.

What benefits do multi-CPU drive controllers offer? Quite simply, doubling the processing power of a hard drive should increase its performance noticeably--and platter drive manufacturers are looking for any way to compete with SDD drives in performance (obviously, the former already has the latter trumped in terms of capacity). The dual CPU architecture should just about max out the efficiency of the big buffer.


Meanwhile, what's up with a pair of actuators? WD employs a traditional actuator to zap the drive heads to the right general area of the sought-after data, and then kicks the show off to a piezoelectric actuator to quickly zoom in on the exact location. The one-two punch is supposed to reduce "short" seek times to right around 0.4 milliseconds.

That's a heck of a task with four platters each weighing in at 500GB. To extend the life of such dense drives, WD employs NoTouch Ramp Load technology. That means that, unlike CSS (contact start stop) based drives, WD drives make sure the heads and the discs never touch each other.


That all adds up to terrific theoretical performance with a low chance of data loss. We obviously can't test the longevity of hard drives (unless you give us ten or so years to report back), but performance is something we can easily quantify.

Test System and Vantage

A spectacularly huge capacity is one thing, but for some of us the purchasing decision also comes down to performance. That's why we tested out of the trio of drives to see which of them--or, in this case, which one of them--would blast out the most impressive numbers.

We pitted the single Seagate and the two WD drives against PCMark Vantage, SISoft SANDRA's Physical Disk Test Suite, the aging but still worthy HD Tach, and we also timed the loading of three games on a fresh, Windows Vista 64-bit installation. Each test was performed on each hard drive in the exact same fashion. We rebooted the PC in between each test.

Futuremark PCMark Vantage
Simulated Application Performance

This benchmark features real-world computations going on behind the surface. The hard drive specific test wings eight Windows Vista oriented activities at the fixed disc storage system, times each one of them, and then calculates a number based on performance. We present below the individual timings plus the PCMark HDD scores. Note--timings are in seconds and smaller lines are better on this logarithmic graph. The PCMark score is in PC Marks and longer lines are better.

And the WD Caviar Black outpaces Seagate's offering while the RE4 blasts out of the pack and takes the early lead. WD's drives are doing well so far, as the Seagate and the WD Caviar Black come in at more or less of a tie for second.


SISoftware's SANDRA is a full suite of benchmarks, report generators, burn-in tools, and a big bunch of other stuff. We use SANDRA's Physical Disk Test Suite to measure several factors of performance for each of the three hard drives. The graph again is logarithmic to show all of the score bars clearly. 

Physical Disk Benchmark Performance

Here is where the Caviar Black really shines. Look at the numbers, and you'll see it pulled ahead once again. Its lead is slimmer here than it was in the PCMark Vantage test though.

HD Tach Tests

Simpli Software's HD Tach is a low-level drive test for just about every type of non-optical storage. It tests hard drives both internal and external, flash drives, RAID arrays, and more. Of course, we used it on the hard drives featured here to test random access time (lower is better), CPU utilization (ditto), and read performance (higher is better):

HD Tach Benchmark
Data Transfer Speeds

Another slim lead for the WD Caviar Black, but what's this? Look at the CPU utilization scores. This drive chokes the quad-core processor in our test system three percentage points higher than the other two drives.

Will that affect the performance in the real world? It's time to test some raw game loading times and find out.

Game Level Load Times

We timed the loading of three games, Far Cry 2, Resident Evil 5 and Wolfenstein, with these parameters:

  • Each game was installed from Steam to prevent optical disk access during timing. 
  • We started Steam before testing. 
  • We defragmented each drive before testing. 
  • We timed games immediately after they were freshly installed. 
  • We cleared all pre- and superfetch data in between each test. 
  • Timing started when we double-clicked the game's icon in the Game Explorer folder. 
  • Timing ended when the first logo, of any sort, appeared on screen. 
  • We performed each game loading test three times and averaged the results for each drive's performance score.


Game Level Load Times
Get Your Game On

The games each loaded in less than 25 seconds, some faster than others--and some drives spit the game code out faster than others. It seems that the CPU utilization hit the Caviar Black suffered in the previous test didn't whack its load times--it loaded all three games faster than the other two drives.

Our Summary and Conclusion

Clearly, the benchmark victor is the WD Caviar Black. There's a chunky caveat, however. The Caviar Black is $300 at Newegg, versus about $130 for the slightly smaller capacity Seagate Barracuda 1.5TB. Meanwhile, the WD RE4, which performed similarly to the Barracuda, goes for about $290.

With a cache twice as large as its competitor, the RE4 didn't exactly trounce the Barracuda. Interesting; in testing that doesn't exploit the larger cache, the two drives perform very similarly.  Our standard desktop-type usage testing didn't exploit the larger cache pools but that's not to say in an enterprise-class environment, with a higher number of concurrent IO requests or perhaps even repeat larger file transfers, you might see a performance differential. 

Furthermore, we installed games on each of these hard drives as you already know, and we also played them from each drive. In real-world action gaming, we truly didn't perceive a difference from one drive to the next. In fact, in virtually all forms of general computing, we couldn't differentiate which drive we were accessing; they all seemed the same. When access times differ in milliseconds, humans can hardly notice. Only our sensitive benchmark tests could tell the difference.

If you're looking for a very good drive with a large capacity at an excellent price, the Seagate Barracuda 1.5TB is a great choice. However, it's definitely not the speed queen of the bunch. For flat out performance and benchmarks that'll give you bragging rights to spill all over your buddies, save up your pennies and nab the Western Digital Caviar Black 2TB. It's a monster.

WD Caviar Black 2TB


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