Market analyst IDC's Worldwide quarterly disk storage track placed EMC as the leader across RAID, open networkined storage (NAS plus Open/iSCSI San) open SAN (storage area network) and NAS (networked attached storage.

Worldwide external disk storage systems factory revenues posted year-over-year growth of 16.2%, totaling just under $6.1 billion, in the fourth quarter of 2010 (4Q10). 

For the quarter, the total disk storage systems market grew to just shy of $8.3 billion in revenues, representing 14.3% growth from the prior year's fourth quarter. Total disk storage systems capacity shipped reached 5,127 petabytes, growing 55.7% year over year.

EMC maintained its lead in the external disk storage systems market with 26.0% revenue share in the fourth quarter, followed by IBM in second and HP in third with 16.3% and 11.6% market share respectively. NetApp ended the quarter in fourth position, with 10.3%. Hitachi and Dell were statistically tied* for fifth with 8.7% and 7.9% respectively.

Given the recent acquisitions of Isilon and Compellent, IDC notes that for 4Q10, Isilon's and Compellent's share in the total external disk storage systems market was 0.78% and 0.55% respectively.

Top 5 Vendors, Worldwide External Disk Storage Systems Factory Revenue, Fourth Quarter of 2010 (Revenues are in Millions) 

Vendor	4Q10 Revenue	4Q10 Market Share	4Q09 Revenue	4Q09 Market Share	4Q10/4Q09 Revenue Growth
1. EMC	$1,582	26.0%	$1,252	23.9%	26.3%
2. IBM	$996	16.3%	$889	17.0%	12.0%
3. HP	$704	11.6%	$641	12.2%	9.8%
4. NetApp	$630	10.3%	$438	8.4%	43.7%
T5. Hitachi	$533	8.7%	$411	7.8%	29.7%
T5. Dell	$483	7.9%	$426	8.1%	13.4%
Others	$1,167	19.1%	$1,187	22.6%	-1.7%
All Vendors	$6,093	100.0%	$5,244	100.0%	16.2%

"The fourth quarter of 2010 continued the trend of economic recovery, and helped close a successful year for disk storage,"said Liz Conner, senior research analyst,Storage Systems. "Aiding in the fourth quarter gains, and all of 2010, was the continued growth of network storage, growing 21.7% from 4Q09 to 4Q10 and 25.7% from 2009 to 2010. Reduction in IT budget constraints has allowed end users to take advantage of vertical and use-case specific network storage products introduced in the past 12 to 18 months."

Open Networked Disk Storage Systems
The total open networked disk storage market (NAS Combined with Open / iSCSI SAN) grew 21.7% year over year in the fourth quarter to $5.1 billion in revenues. EMC continues to maintain its leadership in the total open networked storage market with 29.7% revenue share, followed by IBM with a 15.2% revenue share.

In the Open SAN market, which grew 15.1% year over year, EMC was the leading vendor with 20.1% revenue share, followed by IBM in second and HP in third with 19.0% and 15.4% share, respectively.

The NAS market grew 41.3% year over year, led by EMC with 52.8% revenue share and followed by NetApp with 23.7% share. The iSCSI SAN market continues to show strong momentum, posting 42.1% revenue growth compared to the prior year's quarter. Dell led the market with 32.6% revenue share, followed by HP in second and EMC in third with 14.7% and 13.4% market share respectively.

"The high-end segment (average selling price $250,000 and over) was seasonally strong in the fourth quarter, showing the highest sequential growth across all storage segments,"said Amita Potnis, senior research analyst, Storage Systems. "After significant declines during the 2009 crisis and the strong recovery in 2010, the high-end revenue market share is now 30.2%, thus bouncing back to the 2008 pre-crisis levels. There were multiple drivers beyond the remarkable growth in high-end systems, including demand for storage consolidation and datacenter upgrades supported by new product push from a number of vendors."