SiSoft Sandra - The Diagnostic Tool, Q & A - CPU Detection

This document provides some frequently asked questions about SiSoft Sandra. Please read the Help File as well!

Q: Some of the information in Mainboard Information is wrong!
A:
Sandra asks the BIOS for most of the information shown. Many BIOSes (even those released in 1999) still contain many bugs in the DMI core. While Sandra double-checks most of the displayed information, there is no way to check all internal information (e.g. card slots). The only fix is for you to upgrade your BIOS by obtaining a newer version (see Links) and flash it.

Even if you do have the latest version, the DMI core needs to be configured correctly by the vendor. Only major vendors like Compaq, HP, etc. bother to do this, most OEMs do not. If you do spot incorrect information (double check with the board's DMICFG utility - should be on the CD that came with the board), contact the manufacturer and let them know.

Q: My CPU is not detected correctly!
A:
Make sure you do the following:

Q: My Pentium III/Xeon III is not detected correctly.
Q: Sandra does not detect the KNI/SSE instructions!
A:
Update to Sandra version 5.0 or later.

Q: My Pentium III/Xeon III serial number is not displayed!
A:
The serial number may be disabled by the BIOS. See the mainboard manual for information on how to enable it.

Q: How can I turn off the serial number of my Pentium III/Xeon III?
A:
The serial number can be disabled by the BIOS in some cases. Check the mainboard manual for information on whether this feature is available. If not, Intel has instroduced an utility which can disable it.

Q: My Cyrix MII CPU is detected as a 6x86MX!
A:
The Cyrix MII is nothing more than a 6x86MX made from .25u silicon that runs at higher speeds (PR266+). Cyrix only changed the name to match the PII. IBM still uses the old name.

Q: My Celeron/Pentium II Xeon is not detected correctly.
A:
Upgrade to Sandra version 2.34 or later.

Q: My Pentium II is detected as a Celeron!
A:
Make sure the L2 cache is enabled (see CPU information). If it is not, go to BIOS Options and turn it on. If you have a PII 266 or faster, turn L2 ECC on as well. A PII with no cache is essentially a Celeron.

Q: My Pentium II Xeon is detected as a PII!
Q: My Pentium II is detected as a Xeon!
A:
Intel itself does not provide a way to accurately tell them apart in software without relying on undocumented processor functionality. These algorithms may crash or lock the system completly so they are not used by default. The BIOS can distinguish them properly since the Xeon uses Slot2 while the PII uses Slot1. So a mainboard which knows which type it is has no trouble telling them apart - unlike software programs.

Q: My Pentium II OverDrive for Pentium Pro is not detected correctly.
A:
Upgrade to Sandra version 4.20 or later.

Q: Sandra does not detect the 3DNow! instructions on the AMD K6-2/3, IDT WinChip 2-3D/3/4, Cyrix 6x86 MIII!
A:
Upgrade to Sandra version 4.20 or later.

Q: My IDT C6 WinChip CPU is not detected correctly.
A:
Update to Sandra version 2.01 or later.

Q: My IDT WinChip 2/2-3D is not detected correctly.
Q: My Cyrix MediaGXm CPU & speed is not detected correctly.
A:
Update to Sandra version 4.20 or later.

Q: My Rise mP6 CPU is not detected correctly.
Q: My IDT WinChip 3/4 CPU is not detected correctly.
Q: My Cyrix 6x86MIII CPU is not detected correctly.
Q: My Cyrix MediaGXi CPU is not detected correctly.
A:
Since these CPUs have not been released yet, they cannot be detected.

Q: My Cyrix 6x86MX/MII's speed is not detected correctly.
A:
This is not a bug. The actual speed of the CPU is different from the Performance Rating (PR). Here are the Official ratings:

Processor Actual Speed (MHz) PR-Rating Competitor
6x86MII-PR450 400=4x100 450 Pentium II 450 or
Celeron 466 or
AMD K6-3 450
6x86MII-PR400 380=4x95 or
360=4x90 or
350=3.5x100 or
333=3.5x95 or
333=4x83
400 Pentium II 400 or
Celeron 400 or
AMD K6-3 400 or
AMD K6-2 400
6x86MII-PR366 315=3.5x90 or
300=3x100 or
300=4x75 or
292=2.5x83
366 Pentium II 350 or
Celeron 366 or
AMD K6-2 350
6x86MII-PR350 285=3x95 or
270=3x90
350 Pentium II 350 or
AMD K6-2 350
6x86MII-PR333 266=4x66 or
263=3.5x75 or
250=3x83 or
250=2.5x100
333 Pentium II 333 or
CeleronA 333 or
AMD K6-2 333
6x86MII-PR300 240=4x60 or
237=2.5x95 or
233=3.5x66 or 225=2.5x90 or 225=3x75
300 Pentium II 300 or
AMD K6-2 300
6x86MX-PR266+ 208=2.5x83 266 Pentium II 266 or
Celeron 266 or
AMD K6 266
6x86MX-PR233+ 200=3x66 or
188=2.5x75 or
166=2x83
233 Pentium II 233 or
AMD K6 233
6x86MX-PR200+ 180=3x60 or
166=2.5x66 or
165=3x55 or
150=2x75
200 Pentium MMX 200 or
AMD K6 200
6x86MX-PR166+ 150=2.5x60 or
150=3x50 or
138=2.5x55 or
133=2x66
166 Pentium MMX 166 or
AMD K6 166
6x86MX-PR150+ 125=2.5x50 or
120=2x60
150 Pentium MMX 150
6x86MX-PR133+ 110=2x55 or
100=2.5x50
133 Pentium MMX 133

Also, you'll need to update to Sandra version 1.20 or later. Do note that using a bus speed or multiplier different from the stated will yield a different PR rating. Some combinations may result in a higher PR rating even if the internal core speed is lower.

Q: Why was the PR-ating developed?
A:
Clock frequency (MHz), while important, is no longer an accurate or consistent measure of CPU performance. Architectural differences between processor designs add another variable to the equation. With the PR-ating in place, a PC buyer can easily evaluate all personal computer processors for a given performance category - without scrutinizing the architectural merits of the different processors.

Q: How does the PR-ating work?
A:
The PR-ating process uses a standardized system configuration and application-based benchmark tests to establish a performance, or 'PR', rating relative to a Pentium processor of a given frequency (MHz). This levels the playing field and allows the measurement of relative processor performance under real-world conditions, regardless of the processor's clock speed (MHz) or architecture.

Q: What benchmark test is used in the PR-ating?
A:
Ziff-Davis WinStone is used because it is a real-world, application-based benchmark that contains the most popular software applications (based on market share) that run on a Pentium processor. WinStone also is the most widely used benchmark, and is freely distributed and available.

Q: My Cyrix 6x86's speed is not detected correctly.
A:
This is not a bug. The actual speed of the CPU is different from the Performance Rating (PR). Here are the Official ratings:

Processor Actual Speed (MHz) PR-Rating Competitor
6x86-PR200+ 150=2x75 200 Pentium 200
6x86-PR166+ 133=2x66 166 Pentium 166
6x86-PR150+ 120=2x60 150 Pentium 150
6x86-PR133+ 110=2x55 133 Pentium 133
6x86-PR120+ 100=2x50 120 Pentium 120
6x86-PR90+ 80=2x40 90 Pentium 90

Also, you'll need to update to Sandra version 1.14 or later. The 6x86 supports only the 2x multiplier so for the PR200 you need to use a 75MHz bus speed which not all boards and chipsets support.

Q: Why is there a plus mark in each 6x86 processor name?
A:
For the 6x86 processor, a P+ designation is used to indicate better performance. WinStone 6x86-Pxxx+ > WinStone Pentium-xxx -> xxx = P-rating or Pentium megahertz. For example, a 6x86 processor with a P-rating of "P166+" (regardless of processor name and clock speed) indicates performance faster than a 166 MHz Pentium processor. The plus mark indicates performance that consistently exceeds the same Pentium processor megahertz level.

Q: My AMD K5's speed is not detected correctly.
A:
This is not a bug. The actual speed of the CPU is different from the Performance Rating (PR). Therefore:

Processor Actual Speed (MHz) PR-Rating Competitor
K5-P200 133=2x66 200 Pentium 200
K5-P166 117=1.75x66 166 Pentium 166
K5-P150 105=1.75x60 150 Pentium 150
K5-P133 100=1.5x66 133 Pentium 133
K5-P120 90=1.5x60 120 Pentium 120
K5-P100 100=1.5x66 100 Pentium 100
K5-P90 90=1.5x60 90 Pentium 90
K5-P75 75=1.5x50 75 Pentium 75

Also, you'll need to update to Sandra version 1.16 or later.

Q: My 6x86, 6x86MX is manufactured by IBM but shows up as a Cyrix chip.
A:
The 6x86 family is designed by Cyrix (now part of NS) and manufactured by Cyrix, IBM and SGS Thompson. It is still the same chip no matter who made it.

Q: My Intel/AMD/etc. CPU is detected as a Generic CPU.
A:
It is not possible to reliably detect the manufacturer of old (earlier than 1994) processors. All those CPUs are classified as "generic". This generally applies to 486 and 386 chips.

Q: My IBM Blue Lighting DX3 CPU is detected as a Cyrix 486DX4 CPU.
A:
The IBM Blue Lighting is a Cyrix 486DX4 CPU made by IBM.

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