how to measure K6-2+ cache performance ?

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Jolaes76
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Joined: Thu Aug 11, 2011 4:28 am

how to measure K6-2+ cache performance ?

Post by Jolaes76 » Thu Aug 11, 2011 4:36 am

Hi everyone,

I need some advice on how to measure cache performance on a GA-5AX motherboard. I have a K6-2+ 570 Mhz processor and 512 MB RAM. I want to know whether I should disable the 256 kb onboard cache or not (to achieve best possible performance). The RAM, I think, should pose no problem (I have 2 pieces of CAS2 133 Mhz modules)

So, all in all:
-what benchmarks to use ?
-enable or disable onboard cache ?
-keep all RAM or remove a 256 MB module ?
-are there useful WCPREDIT tweaks for this motherboard? (specific instr needed)

Please share your knowledge. Thank you very much in advance.

DonPedro
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Posts: 575
Joined: Wed Jul 27, 2005 2:11 pm

Post by DonPedro » Fri Aug 12, 2011 8:45 pm

hello,

re what benchmarks to use: some benefit of available cache, others don't. for example, everest home 2.20 shows better read/write scores when cache is disabled. while for example compression tools like 7-zip and winrar LOVE cache (both feature inbuilt benchmark routine, so you can see for yourself). should you decide to see everest scores you are fine with version 2.20. this is the last free version, it covers well k6-hardware, and you will find dozens over dozens of results here at k6plus to compare with.

It is my experience that in many cases "synthetic" bench tools show a higher memory score when cache is disabled, but in reality (office usage) you are better off with cache enabled.

how much memory your system is able to cache depends on the chipset's revision. with version "G" and above you should certainly be fine, lower versions cache only 256 mb of ram (with exceptions in both directions). but be that as it may I would suggest to use both modules because a) the k6-plus cpu is able to cache 4gb of ram anyway and b) memory - disk - swapping will occur less often and this has the biggest performance impact under all circumstances.

re wpcredit tweaks: oh yes, they exist but unfortunately I can't tell you right now, because I can't remember exactly and my old machine is out of reach at the moment. I hope I have kept recordings about what bits to set .... I will report back whether I was able to locate some information.

in the meantime could you please run read/write/latency benches with everest home 2.20 and post the results so that we know how your system is doing?

Jolaes76
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Posts: 9
Joined: Thu Aug 11, 2011 4:28 am

Post by Jolaes76 » Sat Aug 13, 2011 11:41 am

Thanks for the info so far!

Just before reading your post, I got another CPU, a K6-III+ 400 Mhz ATZ.
Here are the benchmark results from this new processor which seems to do a little better in games so I decided to keep it instead of the K6-2+.

The last stable overclock of this system is 550 Mhz (110 x 5), all other combinations either require too much voltage (above 2.4V) or stress PCI/AGP too much for my liking.

BIOS CMOS settings right now:

external cache disabled
host dram c mode bypass

(if I enable onboard cache, I MUST set dram cycles to SYNC and Everest gives much worse RAM results, see below)

DRAM timing fast (means 2-2-4-5)
Ram latency 2
Pipeline enabled

Primary Frame Buffer all
VGA frame buffer Enabled


I also applied some Central Tweaking Units tweaks, these yielded the best results so far:

Write Allocation: Enabled to 508 MB, including 15-16 MB range
Write Ordering: Disabled (fastest)
MTRR0 enabled to video adapter memory range (128 MB): write combined


At this speed Everest Home Edition 2.20 says>

memory read 386 MB/s
write 145 MB/s
latency 193.3

If I set DRAM to SYNC and also Enable onboard cache:

memory read 366 MB/s
write 143 MB/s
latency 198.7

I have yet to examine whether this decreases 3DMark2000 scores or not.

DonPedro
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Posts: 575
Joined: Wed Jul 27, 2005 2:11 pm

Post by DonPedro » Mon Aug 15, 2011 8:34 am

Jolaes76,

your numbers seem to be ok, but unfortunately you started with raising fsb to 110 mhz so I can't tell you how well you are doing, I only have numbers to compare with at 100 mhz. so please start from there and once you maxed out tweaking you could raise fsb again.

one thing is obvious from what you report: you still have ras-precharge-time set to 4. you can change this down to 2 by using wpcredit / wpcrset.

so from the download section pick this tool and also the appropriate pcr data-file for ali5-chipset which you use to feed wpcredit with. place the pcr-files into the same folder where wpcredit is located.

when you start wpcredit (and it does not automatically load the appropriate pcr-file then click the button "open-pcr" (under file-menue) or do so from the file-menue. feed the tool with the file 10b91541.pcr.

next step is (this is not a must) to set display of registers at "8 bit". you will find the button ... (there are others for 16 bit or 32 bit).


ras-precharge-time:
you find the corresponding bits in register 48h (hex) - just place the focus/cursor on junction of col 08 and row 40. there bits #3 and #2 are are to be both set to "1" which equals 2 clocks.

how-to:
in order to manipulate the bits you have to place the cursor at the bottom of the window where it reads "bin ........" at the position of the bits you would like to change. or you click the edit-button (lower right corner). once the cursor is in the bits-field you can use the cursor keys (left/right) to go through them.

BE AWARE and never forget that position (bit #) starts from right to left, so the most right bit is "bit 0"!

while your cursor is placed at a bit-position you will see in the right pane of the window that the according bit-definition is "highlighted" via an asterisk.
so in order to change a bit value (which is either a 0 or a 1) there is nothing else to do than key in a 1 or a 0 to overwrite the current setting. be aware also that once you press 1 or 0 the cursor moves to the next (previous) bit-position.
changes are not carried out until you click the "set"-button (lower right corner) or press return.

when you successfully changed settings (without hanging the pc, it sometimes happens, especially when you are experimenting) then you probably immediately run everest again to see how the setting changed the benchmark numbers.

once you are done you can save your register-settings in a file and load it again conveniently without going through the messy process again.

in case your system is set with mb-cache off you probably set "internal page detection" to active state (1). you will find the setting at register 49h bit 1. (cache MUST be turned off otherwise system hangs)

you should also check "enhanced page mode" (reg 49h, bit 3) (set to 1) and "enhanced page mode counter" (reg 5F, bit 7 and 6 both set to 1s give value 16).

never try to enable/disable mainboard cache from within wpcredit, this surely hangs the system.

once your settings are fine you probably would like the system start with them automatically. for this to achieve you have to use the tool wpcrset. but be aware and warned that this might hang your pc in the early stages of loading the system and then you are out of the loop. if you ever run into this situation you have to boot another system with your broken systems harddisk attached to it and delete/rename the system-driver of wpcrset (wpcrset.sys, located %windows%/system32/drivers for windows NT4, could be another place for w2k or xp).

Jolaes76
Newbie K6'er
Posts: 9
Joined: Thu Aug 11, 2011 4:28 am

Post by Jolaes76 » Mon Aug 15, 2011 11:44 am

DonPedro,

thanks a lot for the guidance.
I will need a few days to tinker with these settings until settling with the best :D

Jim
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Joined: Wed Jan 21, 2004 7:10 pm
Location: Toronto

Post by Jim » Mon Aug 15, 2011 6:15 pm

One other word of advice; - use the 5.5 times multiplier. That will give you much higher memory write speed than either the 5 times or the 6 times.
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noshutdown
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Post by noshutdown » Wed May 02, 2012 1:36 am

DonPedro wrote:Jolaes76,

your numbers seem to be ok, but unfortunately you started with raising fsb to 110 mhz so I can't tell you how well you are doing, I only have numbers to compare with at 100 mhz. so please start from there and once you maxed out tweaking you could raise fsb again.

one thing is obvious from what you report: you still have ras-precharge-time set to 4. you can change this down to 2 by using wpcredit / wpcrset.

so from the download section pick this tool and also the appropriate pcr data-file for ali5-chipset which you use to feed wpcredit with. place the pcr-files into the same folder where wpcredit is located.

when you start wpcredit (and it does not automatically load the appropriate pcr-file then click the button "open-pcr" (under file-menue) or do so from the file-menue. feed the tool with the file 10b91541.pcr.

next step is (this is not a must) to set display of registers at "8 bit". you will find the button ... (there are others for 16 bit or 32 bit).


ras-precharge-time:
you find the corresponding bits in register 48h (hex) - just place the focus/cursor on junction of col 08 and row 40. there bits #3 and #2 are are to be both set to "1" which equals 2 clocks.

how-to:
in order to manipulate the bits you have to place the cursor at the bottom of the window where it reads "bin ........" at the position of the bits you would like to change. or you click the edit-button (lower right corner). once the cursor is in the bits-field you can use the cursor keys (left/right) to go through them.

BE AWARE and never forget that position (bit #) starts from right to left, so the most right bit is "bit 0"!

while your cursor is placed at a bit-position you will see in the right pane of the window that the according bit-definition is "highlighted" via an asterisk.
so in order to change a bit value (which is either a 0 or a 1) there is nothing else to do than key in a 1 or a 0 to overwrite the current setting. be aware also that once you press 1 or 0 the cursor moves to the next (previous) bit-position.
changes are not carried out until you click the "set"-button (lower right corner) or press return.

when you successfully changed settings (without hanging the pc, it sometimes happens, especially when you are experimenting) then you probably immediately run everest again to see how the setting changed the benchmark numbers.

once you are done you can save your register-settings in a file and load it again conveniently without going through the messy process again.

in case your system is set with mb-cache off you probably set "internal page detection" to active state (1). you will find the setting at register 49h bit 1. (cache MUST be turned off otherwise system hangs)

you should also check "enhanced page mode" (reg 49h, bit 3) (set to 1) and "enhanced page mode counter" (reg 5F, bit 7 and 6 both set to 1s give value 16).

never try to enable/disable mainboard cache from within wpcredit, this surely hangs the system.

once your settings are fine you probably would like the system start with them automatically. for this to achieve you have to use the tool wpcrset. but be aware and warned that this might hang your pc in the early stages of loading the system and then you are out of the loop. if you ever run into this situation you have to boot another system with your broken systems harddisk attached to it and delete/rename the system-driver of wpcrset (wpcrset.sys, located %windows%/system32/drivers for windows NT4, could be another place for w2k or xp).
thanks DonPedro, your info has given me some big boost in performance.
i have another question though: is it possible to mod the bios to set the default ras-precharge-time to 2 instead of 4? my board is 5ax aswell.

DonPedro
K6'er Elite
Posts: 575
Joined: Wed Jul 27, 2005 2:11 pm

Post by DonPedro » Mon May 14, 2012 5:32 pm

I don't know of how to mod the bios but maybe you will be fine using wpcrset which, after being programmed accordingly, will automatically set the paramaters to your liking at windows start.

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