Chart guide:
The 'normal' rate is the rate which is achieved with the best normal way possible.
The 'innovative' rate is achieved by knowing the performance flaw and applying our workarounds.
The source of these charts is Membench. For more information click on any chart.
The performance flaw we are revealing in this site is affecting the read and transfer rates not the write rates. Please click on the underlined words in the following tables for more information.

I' Intel Pentium / Pentium MMX-200 MHz

Note: The plain non-MMX Pentium has almost identical results.
System configuration: Intel Pentium MMX-200 on Intel's TX chipset with 64 Mb EDO memory, Matrox Mystique 4 MB graphics card, Quantum Fireball 3.2 hard disk. All three socket 7 processors (Pentium MMX, AMD K6, Cyrix 6x86MX) have been tested on exactly the same computer.
   
As you can see from the chart, on Intel Pentium MMX processors the impact of the innovative method is the most dramatic of all other processors.
So, If all workarounds where applied, an Intel Pentium (MMX) would have:
 

% improvement with workarounds applied:

	Read	Write	Transfer
memory	+68%	+100%	+92%
L2 cache	+51%	+100%	+69%
video	N/A	+17%	+19%

 
 
 
II' AMD K6-200 MHz

System configuration: AMD K6-200 MHz (66*3) on exactly the same system as the previous one.
   
As you can see from the chart, AMD K6 has the flaw to its full degree. Remarks: 

• The read and transfer flaw is not correctable (only a little in the L2 cache); that is the flaw is permanent, the penalty is asserted also on non-sequential accesses. (Though it's correctable on the K5!).
• AMD K6, Cyrix 6x86MX and Pentium II have write allocation, that is on a cache miss, they read a whole line before they write to it, resulting in lower main memory write performance and higher secondary cache write performance. This is a design decision selectable by an internal register; if disabled, write performance is very similar to Pentium MMX.
• The normal video memory write and transfer rates (which are very important in games) are considerably increased by using the innovative methods.

III' Cyrix 6x86MX (M2)-166 MHz (PR200)
 
Note: Usually Cyrix processors carry the designation IBM. IBM just manufactures them, Cyrix designs them; Cyrix is a fab-less chip vendor.

System configuration: Cyrix 6x86MX-166 MHz PR200 (66*2.5) on exactly the same system as the previous ones.
  Remarks:

• The secondary cache's innovative improvements aren't great partly because the secondary cache normal read rate is already high.
• Cyrix 6x86MX, AMD K6 and Pentium II have write allocation, that is on a cache miss, they read a whole line before they write to it, resulting in lower main memory write performance and higher secondary cache write performance. This is a design decision selectable by an internal register; if disabled, write performance is very similar to Pentium MMX.

IV' Intel  Pentium II-233 MHz
 
System configuration: Intel Pentium II-233 on Intel's FX chipset with 64 Mb EDO memory, Matrox Mystique 4 MB graphics card, Quantum Fireball 3.2 hard disk.
  Remarks: 

• On main memory there is virtually no improvement with the innovative method because Pentium Pro and Pentium II support multiple outstanding bus transactions; that is, they issue the next read request before the current is finished, therefore eliminating the flaw.
• Pentium II, Cyrix M2 and AMD K6 and Intel P6 have write allocation, that is on a cache miss, they read a whole line before they write to it, resulting in lower main memory write performance and higher secondary cache write performance. This is a design decision selectable by an internal register.
• Video memory write and transfer rates are very low, because of another design decision to consider the video memory as non-write combining. With the use of some shareware/freeware utilities (e.g. FASTVID) performance increases to the level of Pentium MMX.
• Generally the improvements of our workarounds are clearly visible only on secondary cache read and video memory write and transfer.

V' Cyrix 6x86 (M1)-133 MHz (PR166)
 
Values are similar to Cyrix M2 but with no write allocation and no MMX. For detailed results look in Membench (Cyrix M1 is one of the 8 computers you can compare your computer to).
So, If all workarounds where applied, a Cyrix 6x86-133 MHz would have:
 

% improvement with workarounds applied:

	Read	Write	Transfer
memory	+55%	+42%	+13%
L2 cache	+5%	+29%	-11%
video	N/A	+9%	+7%

 

VI' AMD K5-100 MHz 

K5 is AMD's last generation processor. In contrast to M2 which is an improved version of M1, K5 and K6 have nothing in common; K6 was derived from Nextgen's 786. For detailed results look at submitted results.
So, If all workarounds where applied, an AMD K5-100 MHz would have:
 

% improvement with workarounds applied:

	Read	Write	Transfer
memory	+29%	+35%	+3%
L2 cache	+23%	+97%	+34%
video	N/A	0%	0%

 
The video improvements are 0% due to the slow video card (no name S3 Virge) which can't handle more than 16.7 Mb/sec (we have seen that in 3 different ones).

 
VII' IDT C6 

We haven't been able to find one; if IDT sends us one, we will provide detailed flaw analysis and a dedicated page at the evaluation section of our site.
 

VIII' Intel Pentium Pro-233

System configuration: Intel Pentium Pro-233 MHz (pushed)- 512k internal L2 cache, on a Gigabyte motherboard with Intel's FX chipset with 64 Mb 50 nSec EDO memory, Matrox Mystique 4 MB graphics card, Quantum Fireball 3.2 hard disk.

For remarks look at Pentium II (Pentium II is essentially a Pentium Pro MMX with half speed cache).
For detailed results look in Membench or at submitted results.
So, If all workarounds where applied, a Pentium II-233 would have:
 

% improvement with workarounds applied:

	Read	Write	Transfer
memory	+4%	+1%	+10%
L2 cache	+39%	+2%	+2%
video	N/A	+100%	+64%

 
 

IX' Intel/AMD 486SX/DX/DX2/DX4/DX5 

The same flaw exists also on 486 processors. But due to the different burst length (16 bytes instead of 32), Membench's innovative measurements are entirely incorrect.
 

Proceed to schematic demonstration of the read buffer flaw.

If you can handle it, proceed to in-depth technical analysis.

Results users submitted.
 
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Click one of these buttons to go to the evaluation section.
   

For questions, go to the Q&A page.
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