Price and Performance Comparison for HDDs and HyperDrive4s and RAMSAN SSDs

For two good white papers on the advantages of SSDs over HDDs see...

www.texmemsys.com/files/f000173.pdf
www.texmemsys.com/files/f000174.pdf

Here is the comparison between a Western Digital Raptor Hard Disk, a HyperDrive4 and one 200 MB/s 50,000 IOPS 20 Microsecond latency port of what used to be the entry level RAMSAN SSD by Texas Memory Systems...

Capability	WD740ADFD Raptor	HyperDrive4 revision3	RAMSAN 120
Sustained Transfer Rate	77 MB/s	120 MB/s	200 MB/s
IOPS 100% random 512Byte files	270	44,000	50,000
Access Time	8.4 milliseconds	1 microsecond	20 microseconds
Power Fail	Non volatile	Passive Autobackup to HDD	Active Autobackup to HDD
Battery Backup Length	Not needed	3 hours or 6 hours	30 mins?
ECC Data Scrubbing	No	No	Yes
IBM Chipkill Technology	No	No	Yes
Memory Capacity	36GB, 72GB	0GB - 16GB	8GB
Storage Medium	Rotating Glass Platter	Registered ECC DDR	Registered ECC DDR
Expandable Capacity	No	Yes	No
Takes regular memory modules	No	Yes	No
Form Factor	3.5" Drive	5.25" CD Drive size	1U Rackmount
Power Consumption	13 Watts	13-15 Watts	250 Watts
Weight	0.7Kg	1.15 Kg or 1.3 Kg	20 Kg
Mechanical Failure?	Yes	No	No
Price	£110	£1199 (0GB), £1799 (8GB), £2399 (16GB)	£14,685

The 16GB HyperDrive4 is 160x faster in IOPS than the Raptor and 22x more expensive. The 8GB RAMSAN 120 is 185x faster in IOPS per port than the Raptor and 133x more expensive but only half the capacity of the HyperDrive4!

Here is the comparison between 4 RAID0 Raptors 4 RAID0 HyperDrive4s and a RAMSAN 120 with both ports connected by a fibre switch. The RAID card used was a Silicon Image 3124-2 chip 4 port SATA RAID card with the latest SATARAID5 drivers from Silicon Image.

Capability	4x RAID0 WD740ADFD Raptor	4x RAID0 Sil3124-2 HyperDrive4 revision3	RAMSAN 120
Sustained Transfer Rate	230 MB/s	400 MB/s	400 MB/s
IOPS 100% random 512Byte files	500	104,000	100,000
Access Time	8.4 milliseconds	5-10 microseconds	20 microseconds
Power Fail	Non volatile	Passive Autobackup to HDD	Active Autobackup to HDD
Battery Backup Length	Not needed	6 hours	30 mins?
ECC Data Scrubbing	No	No	Yes
IBM Chipkill Technology	No	No	Yes
Memory Capacity	144GB, 288GB	0GB - 64GB	8GB
Storage Medium	Rotating Glass Platter	Registered ECC DDR	Registered ECC DDR
Expandable Capacity	No	Yes	No
Takes regular memory modules	No	Yes	No
Form Factor	4x 3.5" Drives	4x 5.25" CD Drives	1U Rackmount
Power Consumption	52 Watts	52-60 Watts	250 Watts
Weight	2.8 Kg	5.2 Kg	20 Kg
Mechanical Failure	Yes	No	No
Price	£110	£4999 (0GB), £5599 (8GB), £6199 (16GB), £7399 (32GB), £8599 (48GB), £9799 (64GB)	£14,685

4 RAID0 HyperDrive4s outperform a RAMSAN 120 in speed and they cost half as much for twice the capacity!!

Here is the comparison between 32GB of HyperDrive4 storage in the form of 2 RAID0 HyperDrive4s and the 4 ported RAMSAN 325C, with all 4 ports connected by a fibre channel switch.

Capability	2x RAID0 Sil3124-2 HyperDrive4 revision3 fully populated	RAMSAN 325C max capacity
Sustained Transfer Rate	218 MB/s	800 MB/s
IOPS 100% random 512Byte files	77,000	200,000
Access Time	5-10 microseconds	15-20 microseconds
Power Fail	Passive Autobackup to HDD	Active Autobackup to HDD
Battery Backup Length	3 or 6 hours	30 mins?
ECC Data Scrubbing	No	Yes
IBM Chipkill Technology	No	Yes
Memory Capacity	32GB	32GB
Storage Medium	Registered ECC DDR	Registered ECC DDR
Expandable Capacity	No	No
Takes regular memory modules	Yes	No
Form Factor	2x 5.25" CD Drives	3U Rackmount
Power Consumption	26-30 Watts	250 Watts
Weight	2.3 or 2.6 Kg	32 Kg
Mechanical Failure	No	No
Price	£4,800	£48,000

The RAMSAN is 3x faster in IOPS although not much faster per port (50,000 IOPS) and it is 10x more expensive. If you need 32GB of lightening fast storage, at least an order of magnitude faster in IOPS than hard disk arrays can manage, then 2 RAID0 HyperDrive4s are plainly the Value Solution.