UNIX vs Windows• History • Reputation• Performance• Security• Stability• Cost• Usability

History• UNIX

– Developed since early 70th in AT&T Bell Labs

– Originally no graphical interface, later added

– Networking Centered

– Multi user environment

• NT– Developed

between 1988 and 1993

– Strong emphasis on stability and performance

– First true networking OS from Microsoft

– Originally Single user

Reputation: Suck-Rule-o-Meter

Windows

Unix

Linux

VMS

SolarisOpenBSDOS/400

OS/2NetBSDMacOSxMacOS

AmigaOSBeOSFreeBSD

-8000 -6000 -4000 -2000 0 2000 4000 6000

Suck-Rule-o-Meter over Time

July 1998 May 2000 hitgrowth Windows 1298:185 = 7.0:1 4225:514 = 8.2:1 3.2 Linux 205:952 = 1:4.6 470:2903 = 1:6.2 2.9 MacOS 40:364 = 1:9.1 48:80 = 1:1.7 0.32 FreeBSD 3:78 = 1:26 7:598 = 1:85 7.5 Unix 228:278 = 1:1.2 160:332 = 1:2.1 1.0 VMS 21:39 = 1:1.9 24:50 = 1:2.1 1.2

• Hitrate went down for Apple• People hate Windows today more than they used to• UNIX reputation has improved• Keep in mind that this does not reflect the average user but

rather programmer or tech wiz.

Security: UNIX vs NT• Study by Hedbom and Lindskog• Conclusion:

– Similar Security Features– NT somewhat more ambitious (well it is

younger)

Weaknesses• Bypass of intended controls

– Password attacks: Capture, guessing– Utilizing weak authentication

• Active misuse of resources– Resource Exhaustion

• Passive misuse of resources– Search for weak configuration

Password Attacks• Capture:

– Legacy problem for both UNIX and NT (old protocols and compatibility)

– Both OS transmit under certain conditions Password as plain text

• Guessing:– NT password storage is easy to crack into– UNIX password storage can be overly

accessible • (usually there should be 2 file, a /etc/passwd and

a /etc/shadow that actually contains the passwords)

Resource Exhaustion• Freeze the system by keeping it busy

– NT: Priorities from 1-15– A program with 15 enters an infinite loop– Problem: In NT the process decides about

its priority

– UNIX: process has no access to priority except for lowering it

– Number of processes per user are limited– No Problem

Conclusion• There is no significant difference in

security between UNIX and NT• A lot depends on the configuration

and UNIX has more configuration options to secure things

Performance• NT can’t yet handle the complex and

powerful application that UNIX has• Mostly due to memory management issues“Compaq says that it is selling systems with the

UNIX operating system because Windows NT does not correctly run Java programs (a newer language that decreases the amount of time and money to develop software). It has judged Windows NT inadequate to handle server tasks for large networks (many computers connected together to share information) “

Performance Study• Windows NT finished dead last overall in a

comparison with five different versions of the Unix operating system, concluded a market research firm that assessed the latest versions of these operating systems

• The company ranks the major Unix variants and NT each year using a scorecard that judges six factors. Windows NT ranked last in every area except one.

• However, "Even the Enterprise Edition of Windows NT Server 4.0 trails Unix in every area except for PC client support," D.H. Brown said in a statement.

• "NT still falls short of Unix for advanced Internet protocols and extensions. NT also lags in features for scalability, reliability, availability, serviceability, and system management," the study said.

Usability• NT has a very user friendly interface• NT requires less sophistication from

user than UNIX• The Windows interface in UNIX is not

as nice as NT• Fewer user application programs for

UNIX than NT• More industry strength applications

(Data Bases) on UNIX

Stability• Despite the fact that NT is much more

stable than earlier Windows OS, it still has lower reliability than UNIX

• NT can crash when a buggy application crashes (Blue Screen of Death)

• Memory leaking that eventually decays performance – lack of cleanup and defragmentation

UNIX is the choice for critical tasks

Cost• NT is costly due to the licensing • UNIX application licenses are cheap in

bulk• Culture of Freeware (GNU licensing) on

UNIX where as freeware for significant applications are rare under NT

• Windows requires more software updates and hardware replacements over time

Case: 500 student system

Hardware Software Unit Cost Total Cost (504 users)

At work: 17-inch Dell GX150; 128 MB of RAM, 20 GB hard disk, 900-MHz Celeron

Windows 2000 Office 2000

$1,219 $479 $855,792

At home: 15-inch Dell 2100 with 256 MB of RAM & network card

XP/ Office $1,436 400 users because of some sharing $574,400

Rack of four Dell Poweredge 2550; 2 x 1-GHz PIII, 2 GB of RAM, 36 GB disk, dual controllers 1 TB PowerVault shared storage

Windows 2000 Advanced Server Back Office 2000 499 CALs

$84,421 $3,999 $232

$204,188

School Total $1,059,980

Parent Total $574,400

Start-up total $1,634,380 (All prices are from the vendors Web sites as of September 19, 2001.)

UNIX costHardware Software Unit

Cost Total Cost

At work: 500 x 17-inch SunRay smart displays and one Sun 4800 with 12 GB of RAM, one 2 x 750 CPUs, 2 TB SCSI Disk

Solaris with all needed application software

$621,470 $621,470

Administration workstation: SPARCstation 10; 512 MB of RAM, 2 x 20 GB disk, CD-ROM & floppy drives, 21-inch monitor

Solaris $5,345 $5,345

At Home: Dell Optiplex 17-inch with Caldera Linux

OpenOffice and related open source tools

$1,269 $507,600

Cost to College $626,815

Cost to Parents $507,600

Start-up total $1,134,415

Running cost over 5 years

• Administration effort much higher for NT solution– 1 part time for UNIX– At least 4 full time for NT

• UNIX amortizes over 5 years, NT does not– A 5 year old UNIX machine can very well

handle today’s work– PC environment needs upgrade every 2 years– (the PC philosophy is that each new

generation makes the old one obsolete)

Sum after 5 years

Cost Source Windows Cost Estimate Unix Cost

Estimate

Percent Savings with Unix

Initial Capital Cost $1,634,380 $1,134,415 31%

Support Staff 4 x $45,000 x 5 years $900,000 1 x $65,000

x 5 years $325,000 64%

24 month software refresh

2 x $479 x 504 2 x $400 x 349

$482,832 $279,200 100%

36 month hardware refresh 904 x $1,219 $1,101,976 100%

Parent total $1,341,209 $507,600 62%

School total $3,057,179 $951,815 69%

Total Estimate $4,398,388 $1,459,415 67%

Case 5000 user in Manufacturing

Cost Source Windows Cost Estimate Unix Cost

Estimate % Savings with Unix

Initial capital cost $11,219,808 $9,965,000 12%

Support Staff 165 x $45,000 35 x $60,000

$37,125,000 $2,100,000

45 x $65,000 $14,625,000 63%

24 month software refresh

2 x $3,585,000 $7,170,000 100%

36-month hardware refresh $7,263,972 100%

Total Estimate $64,878,780 $24,590,000 62%

More Implication Productivity Paradox

• UNIX architecture has much more redundancy– If one server fail, others are still able to take over

the job• Fewer staff people means they know more• The productivity effect of failure reduction

– 161 desktop application crashes per day – Users avoid experimenting with the system and

never learn to use it effectively– 5,000 users like PolyOne with annual revenues in

the range of $3 billion. For a company this size, a 1 percent decrease in productivity due to user failure to use the application suite properly and crashes amounts to a $150 million revenue hit in five years

Summary• Stability ->UNIX• Performance -> UNIX• Reputation -> UNIX• Security no winner• Usability -> NT• Cost ->UNIX