Seagate Barracuda ES.2 1TB SAS Hard Drive

0 thumbs up

Upon first glance, the Barracuda ES.2 SAS looks like any standard 3.5" SATA hard drive. Visually, it’s hard to see any difference between the Barracuda ES.2 SAS and SATA models. However, upon closer inspection, one can see that the power/data connector is slightly different compared to what you would see with a standard SATA hard disk.


ES.2 SAS 1 TB - Top


ES.2 SAS 1 TB - Bottom


SAS hard drives share the same physical cables as SATA hard drives, but they use a single connector which has data and power in a single connector. It’s pretty confusing for end-users to understand, but basically what you need to know is that SAS hard drives require SAS adapters in order to run in a desktop/tower chassis environment (adapters can cost anywhere from $10 - $50). In a rackmount environment, one can typically use SAS hard drives in standard SATA disk cages.
 


SAS Interface on the Barracuda ES.2


Promise TX2560 SAS Controller


For our tests, we used Promise’s new consumer-targeted TX2560 SAS controller card, which can be had for a mere $70 today (2 x SAS adapters included). Most SAS cards with hardware RAID prcessors price out in the $300+ range, so seeing affordable SAS adapters is definitely exciting to see. Not surprisingly, such a product only provides the very basics for a SAS disk setup, including support for two SAS 3GB/s or SATA-II/300 drives, a PCI Express x1 interface, and support for RAID 0, 1 and JBOD modes. The card utilizes the Promise PDC42819 controller, which is a software-based solution, meaning there is no dedicated RAID processor onboard. However, with only two ports, the need for hardware RAID processing is slim, and the increased latencies of such a solution might hurt single/dual disk performance. We’re just glad to see something finally filling up those PCI Express x1 slots which sit empty on so many of today’s motherboards.

The Barracuda ES.2 1TB SAS drives are nearly identical to their SATA-equipped Barracuda ES.2 brethren. Both the Barracuda ES.2 SATA and SAS drives support up to 1 TB of storage capacity and are housed in a standard 3.5" form factor. Both drives have 7,200 RPM spindle speeds, and both are equipped with 5 year warranties. Both the SATA and SAS variants can sustain 105 MB/s transfer rates at their peak. There are differences, however - and one is somewhat of a major one. For reasons unknown, Seagate decided to strip down the SAS variant and only offer it with 16 MB of cache, whereas the SATA variant has a larger 32 MB of cache on the high-end models. The SAS version also consumes a bit more power, although the difference is a somewhat trivial 1W.
 

  Western Digital Caviar RE2 750 GB Seagate Barracuda 7200.11 SATA Seagate Barracuda ES.2 1 TB SATA Seagate Barracuda ES.2 1 TB SAS
Spindle Speed 7,200 RPM 7,200 RPM 7,200 RPM 7,200 RPM
Platter Count 3 4 4 4
Cache Memory 16 MB 32 MB 32 MB 16 MB
Average Seek Time 8.9ms N/A N/A N/A
Average Latency 4.20ms 4.16ms 4.16ms 4.16ms
Interface Serial ATA-II/300 Serial ATA-II/300 Serial ATA-II/300 Serial Attached SCSI 3 GB/s
Acoustics 28 dBA (Idle)
34 dBA (Seek)
27 dBA (Idle)
29 dBA (Seek)
27 dBA (Idle) 27 dBA (Idle)
MTBF 1.2 Million Hours 750,000 Hours 1.2 Million Hours 1.2 Million Hours
Warranty 5 Years 5 Years 5 Years 5 Years


The Barracuda ES.2 SAS has a few competitors – namely Seagate’s own ES.2 SATA product line which has similar features but a different connector, more cache, and will (likely) sell at a lower price point. Potential buyers will likely be interested in how the drive compares to other similarly classed high-capacity drives. However, in the land of truly high-capacity SAS storage, the Barracuda ES.2 SAS stands alone, as its closest competitor has less than 1/3rd the capacity (300 GB) and costs about three times as much as the ES.2.

Article Index:

0
+ -

LOL seems pointless to me the cost/performance average is so minimal and specialized it makes no point. Get twice the sata drives and memory for the same price and have better as well as a wider performance spectrum with the same additional costs for controllers. This is where ssd's come in they average a 60-80% performance increase over sata for right around the same amount of storage cap. as a SATA drive. I would say 40-65% performance increase over a SCSI drive with a pretty close price margin I would go sata drives twice the capacity and 1/4-1/3% more memory for storage and ssd for my lower storage (speed) amount drives and run it in raid. Therefore for the same rough cost amount I at least double response times and storage times with the memory overhead thrown in for the same (roughly) price margin.dont I?

0
+ -

I don't know too much about SCSI drives, but I was under the impression that their main advantage was their higher RPM. If this new SAS drive has a 7200 RPM speed, what advantage would there be to getting one vs a standard SATA drive?

0
+ -

Okay this review tops it. So you claim the advantage of the drive is so that you can mix and match high perf 15/10k SAS drives with high capacity 7.2k drives.  This is dumb. SAS controllers support SATA drives - how do you think server integrators (look at recent dell poweredge servers eg R900) fit SATA drives with SAS drives?

let's have a look at good ol' wikipedia

http://en.wikipedia.org/wiki/Serial_ATA 

 

The current SATA specification can support data transfer rates as high as 3.0 Gbit/s per device. SATA uses only 4 signal lines; cables are more compact and cheaper than for PATA. SATA supports hot-swapping and NCQ. There is a special connector (eSATA) specified for external devices, and an optionally implemented provision for clips to hold internal connectors firmly in place. SATA drives may be plugged into Serial Attached SCSI (SAS) controllers and communicate on the same physical cable as native SAS disks, but SATA controllers cannot handle SAS disks.

So you just reviewed one of the most useless products i've recently seen. Or you missed the point. I think probably the latter. There must be something different about this drive compared to the SATA one, and it can't just be the connector. Or maybe it is, and they are actually the same drive with the only difference being it takes a SAS connector but does not actually use SCSI commands?

 Brendan

 edit :

LOL seems pointless to me the cost/performance average is so minimal and specialized it makes no point. Get twice the sata drives and memory for the same price and have better as well as a wider performance spectrum with the same additional costs for controllers. This is where ssd's come in they average a 60-80% performance increase over sata for right around the same amount of storage cap. as a SATA drive. I would say 40-65% performance increase over a SCSI drive with a pretty close price margin I would go sata drives twice the capacity and 1/4-1/3% more memory for storage and ssd for my lower storage (speed) amount drives and run it in raid. Therefore for the same rough cost amount I at least double response times and storage times with the memory overhead thrown in for the same (roughly) price margin.dont I?

Ok you have never used 15k scsi drives have you?  They beat traditional 7.2k SATA drives by an enormous margin. They beat raptor/velociraptors by a fair bit too. SSD's have awesome access times but in raw read/write speeds they are still really slow compared to old SCSI tech. Where do you get the 60-80% perf increase from SATA to SSD? that's completely made up, look at a review :

http://www.anandtech.com/storage/showdoc.aspx?i=2982&p=5

ok this is a slow old tech SSD, but the new ones aren't better by miles. 

0
+ -

Seems like this is a drive for the set where the boss won't let you buy a SATA drive and forces you to buy the more expensive 1TB SAS drive. I assume as with most exterprise hardware you get the full enterprise warranty.

0
+ -

 What I want to know is if there is any difference in using the SATA version or the SAS one. Considering that both can be plugged into a SAS raid controller I would think that a test of each drive on the same controller in single and raid configuration would be a real test of whether the drives are actually any different.

0
+ -

audumla:

 What I want to know is if there is any difference in using the SATA version or the SAS one. Considering that both can be plugged into a SAS raid controller I would think that a test of each drive on the same controller in single and raid configuration would be a real test of whether the drives are actually any different.

 

difference is in the warranty and a lot of SAS drives are 10,000 rpm not 7200rpm like this one. I guess if you want sheer capacity you have to make due with less performance. 

0
+ -

Heya Aud,

First, welcome to the forums here. If you look at the article, there are some comparison tests, each drive on its own native controller, SATA and SAS:

http://www.hothardware.com/Articles/Seagate_Barracuda_ES2_SAS_1_TB_/

The base drive platform is indentical though, except for the interface.  I'll ask our editor to chime in here with his thoughts too though.

Thanks!

0
+ -

The only real differences between SAS and SATA interfaces is that SAS supports longer cable length, 10 meters vs 1 meter for SATA, and that SAS drives are mostly 10k or 15k RPM (thus much louder). SATA drives can be used with SAS controllers, but not the other way around. Both interfaces offer the same speed, although SAS interface spec uses higher voltage due to the increase max cable length. I've also never seen hot-swap SATA controllers, but it's pretty common for higher end servers to have hot-swappable SAS controllers.

 SATA doesn't mean that the drive is a desktop drive, there are plenty of enteprise SATA drives which are usually 2.5 inches rather than the standard 3.5 for PCs.

 Anyway, my thinking for why Seagate is releasing these drives is because it's not much more expensive to produce them over the SATA versions and it looks better to the CTO/CIO being a SAS rather than a SATA drive. :) Maybe the cable lenght limit of SATA has something to do with it also.  

Login or Register to Comment
Post a Comment
Username:   Password: