IBM TS7700 - Page 6

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Table 1. Virtual Tape Subsystem Comparison
Feature IBM TS7740 Sun VSM 5 IBM
Score
1
Sun
Score
1
Maximum Number of Virtual Tape
Drives per Single Node/Multi-Node
256/768 256 1
Maximum Number of Nodes 3 (arch. for 8) 2
Maximum Peak Throughput per Node
2
800 MB/s 650 MB/s 1
Maximum Sustained Write Throughput
per Node
3
550 MB/s 613 MB/s 1
Data Compression Ratio – System z 4:1 4:1
Maximum Disk Cache Raw Capacity 6 TB 7 TB 1
Maximum Effective Disk Cache
Capacity (4:1 Compression)
24 TB 28 TB 1
General Availability 2H06 2H06
System z Attachment 1, 2, and 4 Gbps
FICON
(auto negotiate)
2 Gbps FICON 1
FICON Concurrent I/O Support per port 32 16 1
Open Systems Attachment None None
Maximum Number of FICON Channels
per node
4 (4Gbps) 16 See
text on
Perfor-
mance
See
text on
Perfor-
mance
Maximum Number of FC links to real
tape drives per node
2 - 4Gbps paths
to all real tape
drives
None –
channels must
be dedicated
to host, tape
drive and
cluster links
1
Gigabit TCP/IP links 2 0 1
Maximum Number of Real Tape Drives
per node
16 32 1
Maximum Number of Virtual Tape
Volumes
1,000,000 Not limited 1
Synchronous Replication Yes None publicly
announced
1
Asynchronous Replication Yes Yes
On-demand Disk Cache upgrades Yes No 1
On-demand Performance upgrades Yes No 1
Maximum Power
Consumption/dissipation
3.2 KVA; 11.0
KBTU/hour
3.8 KVA;12.4
KBTU/hour
1
Score Totals 10 5
Notes:
1 - This score is a simple binary -- which vendor has better specifications
2 - Depends on lots of things including compression ratio, read/write ratio, block size, etc.
3 - Depends on features and updates installed
Sources: IBM, Sun, and Google