• Welcome to OnlyTech Forums
    An online community for the tech enthusiasts!
    Log in or Register



5 Aug 2011
Reaction score
Everyone needs to store data; the only question is whether the new solid-state drives have overtaken standard hard drives. CHIP puts spinning platters against compete against ROM and reveals the advantages and the disadvantages of both classes.
Most people agree you can never have enough storage space! But in the computer world, where CPUs are already no longer measured by Gigahertz numbers and the prices of notebooks count more than their performance, hard drives are not bought for their capacity alone. Good performance, energy efficiency, and robustness also have to be considered. In this scenario, standard hard disks have the size and price advantages, while on the other hand modern solid state drives offer speed and reliability. Which one will win the battle overall? CHIP invites you to watch our storage format war!

Round 1: Speed
At first, 2 Terabytes of disk space sounds impressive. But what is the use of such giant hard disks when you have to wait for hours to store your data? Today’s 3.5-inch HDDs, are all equipped with SATA 2 interfaces (though SATA 3 will become popular this year) which are found in every current PC and are known to provide solid performance. The current best-selling hard drives have average data transfer speeds of 111 MBps, both during data reading and writing. In practice, this means that copying the entire contents of a DVD onto another hard disk takes nearly 45 minutes. The transfer rate falls around 28 percent with smaller 2.5-inch drives, which are used in notebooks and super-compact desktops. The fastest notebook hard drives on the market today achieve around 80MBps while reading and around 75MBps while writing which is just about OK.

Now Solid State Drives (SSDs) enter the ring—and all hard drives are simply wiped out. The Intel X25-E (and the internally identical Kingston SSDNow E Series) reach data speeds of 243 MBps when reading and more than 206 MBps when writing. The best SSD is nearly twice as fast as a top 3.5-inch hard disk and approximately three times speed of a top notebook hard drive! Even the SSDs in the lower ranges of the price-performance list offer data rates comparable to the fastest HDDs.

And this is not all: the fastest SSDs already achieve the theoretical 3Gbps limit of SATA 2. SSDs will become even faster as soon as SATA 3.0 drives and controllers are available, since this standard doubles the rated speed to 6 Gbps. You won’t even have time for a sip of coffee.

The difference is really striking when you consider access times, i.e. the standby time before which stored data can be accessed. The top-performing Western Digital VelociRaptor manages with very little standby time of just 7 milliseconds while reading. While writing it is as low as 3 milliseconds. In comparison, most conventional hard drives need 15 ms while reading and 10 ms while writing. Notebook HDDs work with access times of upto 15 milliseconds for the same tasks.

The Intel X25-E lowers standby time to almost zero. Only 0.07 milliseconds while reading and 0.05 milliseconds while writing. This is 60 times faster than the VelociRaptor! Clearly the first round goes to solid state drives. But beware: all SSDs are not created equal. The worst Flash drives are extremely sluggish with more than 200 milliseconds of delay while writing. Even the most appalling notebook HDD does not require more than 17 milliseconds.

Round 2: Price-performance analysis

Hard drives had no chance in the speed comparison, but this is not a reason to count them out. Magnetic drives have a very, very strong trump cards to use: the maximum capacity and the price per Gigabyte figures. Today, there are already 3.5-inch hard drives with 2 Terabyte capacities, and notebook drives are hitting 1 TB (though the biggest standard-height drives are still 500 GB) and the pace of development has not slowed down.

And this is frankly enough to hold off the attack of the SSDs for now. The current standard of normal SSDs are available in sizes of up to only 256 GB. The few exceptions which go as high as 512 GB are stratospherically expensive. Though 256 GB is enough for most applications, it’s just not enough for today’s digital films, music and photos.

The price per Gigabyte round just goes against SSDs. A 1 TB 3.5-inch drive should cost no more than Rs 4,500. This works out to 1 GB of space for Rs 4.5 per gigabyte. At present a notebook drive costs Rs 4,800 for 500 GB, which comes to Rs 9.6 per GB.

On the other hand, the fastest Intel X25-E costs US$ 799 (approx Rs 36,900) for only 64 GB! Even the cheapest 32 GB SSD comes for around US$ 100 (approx Rs 4,600). The painful thing for all SSD fans is that they must pay many times more for the comparatively modest 2x performance boost. Also you cannot have high space demands, or you will need to use the SSD solely for applications and add another HDD for mass storage. Clearly the second round goes to HDDs.

Round 3: Electricity consumption

Most users and buyers rarely consider anything beyond the speed, capacity and cost. However SSDs are trying to attract attention to another area: a good modern SSD needs only 1 Watt while reading and 2 Watts while writing data. In comparison with 3.5-inch HDDs, this is a big advantage since the best case scenario for them is 4 Watts on average. However notebook HDDs keep up very well; even reasonably priced ones consume between 0.6 and 2.2 Watts on average while reading and 2.5 Watts while writing. Therefore this round is a draw.

Round 4: Stability

Better robustness is taken for granted with Flash memory. SSDs have no moving parts and can recover from vibrations and shocks better than hard drives which have delicate read heads and thin magnetic platters. For those who use their laptops outdoors, in moving vehicles or in harsh conditions, an SSD is a better choice.
But what about their overall durability? Here, there is still no long-term test to prove which is better. SSDs are still too new, and Flash modules have a limited lifespan. SLC chips can withstand around 100,000 writing circles, but MLC chips can take only around 10,000. That is why manufactures have come up with a variety of techniques to distribute write operations in cycles across the memory area so that no part gets worn out. And just like HDDs, SSDs also come with guarantees of three to five years. Being tested and known, HDDs win out here.

Round 5: Operating Noise
Our final parameter is the amount of noise each type of drive makes. SSDs seem to win here since they have no moving parts making noise at all. However the notebook drive is also not bad: it’s rare to hear even a slight whisper while in operation. In contrast, 3.5-inch hard drives can be heard from quite far away, and the noisiest of them all is the the Western Digital VelociRaptor, which spins at an amazing speed to achieve its fast data rates.
In this round the victory goes to SSDs.

The Result: Undecided!
Which type of drive is better? Even after extensive testing, CHIP reads this result as a draw, because the answer depends on the individual demands of the user. Those who wish for the ultimate in performance with no worries about price and no high memory requirements should go with an SSD. Even laptop owners who travel a lot and expose them to harsh conditions are served well with SSDs. If you are lucky enough to have a laptop with space for two drives, you can get an SSD to boot from and a HDD for bulk storage; a fine balance. For all other users, an SSD is just not worth it. At prevailing prices, one can get a standard hard drive with lots of memory space for very little money.

Source : Chip magazine.
Top Bottom