The Adaptec SCSI Card 3950U2 delivers the performance and flexibility required by today's high bandwidth servers and workstations. This host adapter delivers a combined data transfer rate of 160 MByte/sec across two independent Ultra2 SCSI buses making it a perfect match for high throughput applications such as data mining, streaming video, and scientific modeling.
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DownloadsDocumentationTechnical Specifications

Note: Only drivers that are not included or embedded within a supported operating system are listed below. To see a complete list of supported operating systems see the Product Specifications

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Bios Updates and Other Downloadable Files

Bios Updates and Other Downloads




Microsoft DOS
Microsoft Windows 2000
Microsoft Windows 3.1x
Microsoft Windows 7
Microsoft Windows 95
Microsoft Windows 98
Microsoft Windows Millennium
Microsoft Windows NT
Microsoft Windows Server 2008
Microsoft Windows Vista

Novell NetWare

Novell NetWare Downloads


SCO Unix
SCO UnixWare

Hardware Installation
how to install your adaptec pci card (html 74 kb)
differential scsi (html 68 kb)
ultra2 scsi termination (html 68 kb)
Installing Drivers or Software
cdrom in dos (html 69 kb)
7800 netware instructions (html 81 kb)
7800 family manager set 98 contents (html 68 kb)
installing 98 driver (html 70 kb)
windows 98 issues (html 70 kb)
7800 miniport issues in 95 (html 70 kb)
installing windows nt driver (html 82 kb)
aic7870.dsk options (html 76 kb)
7800 netware contents (html 70 kb)
7800 issues for netware (html 71 kb)
7800 netware notes (html 70 kb)
miniport options (html 70 kb)
7800 diskette contents (html 68 kb)
os/2 driver installation (html 68 kb)
os/2 driver notes (html 77 kb)
7800 os/2 diskette (html 69 kb)
7800 os/2 issues (html 68 kb)
7800 update information (html 67 kb)
installing 2940u2w in netware 3.12 (html 69 kb)
install netware v3.12 (html 70 kb)
7800 fms support list (html 72 kb)
Product Documentation
SCSI Card 3950U2 (PDF )
User Reference for the AHA-3950U2 (PDF 301 KB)
Install Guide for the AHA-3950U2 (PDF 1 MB)
Adaptec Ultra2 SCSI Card Family (PDF )
Use Your Product
scsi<i>select</i> user's guide (html 83 kb)
scsi terms explained (html 77 kb)
sense codes described (html 96 kb)
hotplugging aha-3950u2 (html 67 kb)
Cache Memory
Dual Address Cycle (DAC) provides greater system memory addressabilityTarget mode for supporting clustering,bridge and RAID applicationsMultitasking operating system support (through scatter/gather, disconnect/reconnect, tagged command queuing support)Advanced multimode Ultra2 SCSI I/O cell for supporting Ultra2 (LVD) or single-ended (SE) devicesSupport for 255 simultaneous active SCSI commands per channelJTAG boundary scan to support system level interconnect testing3.3V / 5V PCI interface for providing flexibility for designing high-performance, low-power systemsEnhanced Logical Unit Number (LUN) supports up to a maximum of 32 LUNsI2O-ready system compatiblePCI Hot-Plug compatible
Number of devices
Up to 30 devices

Bus System Interface Type

64-bit Bus Master DMA (backwards compatible w/32-bit PCI)
External Connectors
68-pin High-Density Ultra2 SCSI (Channel A)
Internal Connectors
68-pin High-Density Ultra2 SCSI (Channel A) 68-pin High-Density Ultra2 SCSI (Channel B) 50-pin Ultra SCSI (Channel B) - for use when dedicating Channel B to legacy SCSI support
Data Transfer Rate
Up to 80 MByte/sec on each Ultra2 SCSI channel for total bandwidth of 160 MByte/sec
5 year

Additional Features

  • Two 20-MIPS PhaseEngine RISC processors for fast SCSI command processing
  • Two 512-byte data FIFO buffers for efficient PCI bus utilization