Toshiba XM-6401B SCSI CD-Rom
   Built with an eye toward high performance, Toshiba's 40X XM-6401B.SCSI CD-Rom provides nearly immediate access to data. Smoothly branching between media graphics, and with a fast random access time of only 80ms and a fast data transfer rate of 6MB/sec, the XM-6401B's value is further enhanced by Toshiba's well established  quality, reliability and innovation, all of which contribute to the drive's highly-dependable 100,000 MTBF rate.

But why SCSI?
   There has always been debate over which is the best device interface, and in this debate the answer, as far as performance was concerned, was invariably SCSI.  But times they are a changin'. Rapid advancements in IDE/ATAPI technology is on the brink of toppling the SCSI standard as king of the hill as far as data throughput and now with IDE RAID technology and the universal serial bus (USB) coming into its own, even in a multitasking in a multi-peripheral environment SCSI is losing its edge. 

   Still, if your system is currently endowed with a SCSI interface, either onboard, or through the use of an adapter it is good to know that quality devices are still available and the prices have , although still higher than their IDE/ATAPI counterparts, are coming down.. The SCSI interface  still supports more devices, provides exceptional support for multitasking, more expansion, use of more high-end devices, more types of devices, and still has more performance-enhancing features all of which require fewer system resources. IDE/ATAPI is catching up but, because of its somewhat inefficient use of system resources, still is intended primarily for home and small business workstation PCs that do not require a lot of high-end peripherals, or for those that are cost conscious.

   We purchased the drive as an OEM device at a cost of $80.00USD.  Iit came brown-boxed with an included SCSI  Standard 50-pin ribbon cable and 3-pin audio cable and a leaflet-type user's guide.  Toshiba's XM-6401B is a Fast/Ultra SCSI drive which uses CAV technology.  This means that data throughput increases as the heads move toward the outside of the media and the drive actually fluctuates between 17.3X and 40X as data is read from the inside out at 2,595 - 6,000 KB/sec.  The drive offers an exceptional random access time of 80ms and an average random seek time of 75ms.  The drive does not offer digital audio out but the analog audio port provides good but not exceptional response with a sampling freq. of 44.1kHz, freq.response from 20Hz to 20kHz (3db), a typical signal-to-noise ratio of 83dB and typical total harmonic distortion rate of 0.014%.

XM-6401B - 40X Internal SCSI-2 Specifications

Compatible CD-ROM Standards: Red-Book, Yellow-Book, CD-ROM XA, CD-I Bridge (Photo-CD, Video CD), CD-I, CD-I Ready, CD-G and Multi-session (Photo-CD, CD-Extra, CD-RW, CD-R), CD-TEXT
Access Time:
Average Random Access Time 80ms (40X)
Average Random Seek Time 75ms (40X)
Average Random Full Stroke Time 135ms (40X)
Data Transfer Rate:
Sustained Mode 2,595 - 6,000 KB/s (17.3 - 40X)
Burst (SCSI Interface) 20MB/s Sync.
5 MB/s Async.
Spin Up Time: 3.5s Typ (40X)
Rotational Speed: 8,500rpm (17.3 - 40X)
Buffer Cache Size: 256K
Physical Characteristics:
Dimensions 1.62" x 5.69" x 7.41" (41.5mm x 146mm x 193mm)
Weight 1.98 lbs (0.9 kg)
Output 0.75 volts (rms Typ)
Distortion 0.014% Typ (at 1kHz with 20kHz LPF)
Power Requirements: +12v, +5v (5%)
Ambient Temperature:
Operating 41 to 122F (5 to 50C)
Storage 14 to 140F (-10 to 60C)
Shipping -40 to 149F (-40 to 65C)
Operating Humidity (non-condensing) 8% to 80% (wet bulb 27C max.)
Error Rates:
Hard Read Error - Mode 1 10 -15
Hard Read Error - Mode 2 10 -12
Seek Error 10 -6
MTBF: 1000,000 POH @ 20% Duty Cycle
Mounting Orientation: 20 Horizontal  /  10 Vertical

   Setting up the drive was easy as we did not have to change any of the jumper setting.  There are quite a few of these which allow for setting the device ID on the SCSI bus, parity and termination etc. but since the factory defaults fit easily into our system, we gave the jumper block a quick once-over and moved on.  Basically, it is the same process as setting up an ATAPI CD-Rom which is one of the easier upgrades one might attempt.  Our SCSI host adapter, Adaptec's AHA-2940U2W supports up to Wide Ultra 2 SCSI devices so there was no problem there and the device was properly identified by the host adapter on reboot.

   We tested the drive on a Windows 98 SE system with the following specifications:

Test Configuration for Toshiba XM-6401B

Mainboard Tyan S1598 Trinity ATX
Chipset VIA MVP3 
Processor AMD K6-2 450MHz
Memory 2x64MB PC100
Generic CAS 2
SCSI Host Adapter Adaptec AHA-2940U2W
Hard Drive IBM UltraStar 9ES 4.5G
Ultra2 SCSI
Graphics Adapter Elsa Winner II 16MB Savage4 AGP X2
Operating System Windows 98 SE

In the table below you can see how Ziff-Davis CD Winbench 99 scored the XM-6401B.  While we ran the benchmark 5 times the single iteration below is what we felt was the median overall score

Table of Results

As required by this benchmark's license agreement, you must disclose a summary of the system configuration when quoting any benchmark results.


s Higher scores represent better performance.
t Lower scores represent better performance.
Blue type denotes first place
Red type denotes last place.


Toshiba XM6401B


CD WinBench 99/CD-ROM Access Time (Milliseconds)




CD WinBench 99/CD-ROM CPU Utilization (Percent Used)



CD WinBench 99/CD-ROM Transfer Rate:Inside (Thousand Bytes/Sec)



CD WinBench 99/CD-ROM Transfer Rate:Outside (Thousand Bytes/Sec)



CD WinBench 99/CD-ROM WinMark 99:Overall (Thousand Bytes/Sec)



Basic Info/Date Time


2/26/00 7:12


Basic Info/Benchmark Name

CD WinBench 99


Basic Info/Benchmark Version

CD-ROM Inspection Tests Build 7 CD-ROM Tests Build 28 zdbui32.exe Build 28


Basic Info/Description

Toshiba XM6401B


Basic Info/Tester Name

Lyle Boomer


Basic Info/Tester Organization



Basic Info/Variant 1

100MHz FSB


Basic Info/Variant 2

AMD 450MHz


Basic Info/Variant 3



1. Common test settings: CDROM Drive=e:\ Report CPU Utilization=No



2. The following Windows tasks were running during this test and could affect the test results: WMIEXE.EXE

3. The transfer rate during this test averaged 1200 thousand bytes per second.

   And as you can see in the graph above, the XM-6401B quickly reached its startup data throughput rate of 2,595kb/sec and did proceed to to push data all the way up to the 6,000kb/sec mark so, so far Toshiba was correct in their assessment of the device.  SiSoft's Sandra 99 generated the following results

And Adaptec's SCSI Bench generated the following after 12 sec.

   We have to give high marks to the Toshiba XM-6401B.  The device performed almost exactly as described by Toshiba - this is rather unusual  as most oftern the manufacturer's marketing dept. always puts a best case scenario spin on the devices they describe.
   While I wouldn't recommend rushing out and purchasing a new SCSI host adapter just to use the XM-6401B, if you have a SCSI-based machine currently and have need of an upgrade CD-Rom, you'd have to spend more and search hard to find the kind of performance available with the XM-6401B

You can find out more about the XM-6401B and other fine CD, CD-R and CD-RW drives at Toshiba's web site at  

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