memory timings revisited-forced to oc-p4p800

[robert]

First of all thanks to everyone who answered my first posting about this
subject. The patience exhibited to the "stupid" questions of newcomers is
appreciated.
So I took the advice and set memory to 400mhz manually -- removing the AI
overclocking feature of my p4p800 board. All ok.
Decided then to stop overclocking. Apparently this enables the mysterious
PAT, and anyway I'm not sure why I overclock -- probably just to feel like
I'm getting something for nothing -- so I reset the CPU to 200 (2.8 P4 800
fsb). Computer never comes back on. Try AI "standard" setting. Same thing. I
remove "turbo" setting and computer works. In other words, if I overclock I
can keep "turbo" enabled and the computer seems quite stable. If I return to
the settings that reflect the actual hardware, the computer dies if "turbo"
is enabled. Something contradictory here, yes no? Basically I would like
some opinions on what the best performance settings are. Thanks.

Original message: Can anyone comment on these memory timings from the
program cpu-z? Are they
correct for the memory I have on this motherboard? I would just like to
know if I have the memory working correctly. I have a p4p800 mb, xp pro, 1
gbyte divided in two 512, pc3200 corsair twin memory cards. Bios settings:
MAM enabled, turbo enabled and overclocked 10% (2.8 mhz processor, 800 fsb)
by AI overclocking to 3079 mhz. Computer is stable, but not particularly
fast.

The program gives me:

Size: 1024 (correct)
Channels: dual
performance mode: disabled (WHY DISABLED?)
modules information: Corsair ddr-sdram pc3200
frequency: 146.7 (SHOULDN'T IT BE 400?)
cas latency: 2.5
ras to cas delay: 4 clocks
ras precharge: 4 clocks
cycle time: 8 clocks

 

[Jim Shaffer, Jr.]

Decided then to stop overclocking. Apparently this enables the mysterious
PAT, and anyway I'm not sure why I overclock -- probably just to feel like
I'm getting something for nothing -- so I reset the CPU to 200 (2.8 P4 800
fsb). Computer never comes back on. Try AI "standard" setting. Same thing. I
remove "turbo" setting and computer works.

Lucky you! I turned Turbo on (with the FSB set to 200) and the BIOS won't even
load so I can't set it back. CPU Parameter Reset doesn't work. Clearing the
CMOS doesn't work.

Computer is stable, but not particularly fast.

I'm curious as to what you mean by "not particularly fast", because that's the
reason I was trying to enable Turbo mode. Since I use Linux, I don't have all
the nifty benchmark programs Windows users seem to, but I'm trying to judge it
by the speed it runs SETI@home and POV-Ray. My old system was a Pentium 3 at
700 MHz. The P4 is 4 times as fast, at minimum. Now, I'm not expecting to get
a 4X speedup, but on SETI@home it barely makes a 3x speedup, and on POV-Ray it's
more like 2x! I can get close to 4x speedup on POV-Ray if I recompile it with
SSE math, but I would've thought that 4x the processor speed would've got me a
whole lot closer than 2x the application speed using the generic Pentium code.
Am I misguided?

 

[robert]

Not really qualified to answer this; hope someone else can. However, my own
experience indicates that "turbo" and "standard" provoke exactly the same
problem. You're right, I was lucky that the computer came on again; you can
just tell that it was touch and go. Overclocking manually from 200 to 201
completely eliminates the problem. Perhaps any overclocking, no matter how
small, automatically disengages the "turbo" setting without telling you
this. Or PAT is the problem and overclocking eliminates PAT -- I really
don't know. "Not particularly fast" is a subjective comment; have different
computers in the house, and considering how much the memory and processor
set me back, I expected more -- snap. On the positive side, I can open a
good number of heavy programs, and have them operating simultaneoulsy
without even the hint of a crash; the computer churns on. Is there a
benchmark for this?

 

[Paul]

Not really qualified to answer this; hope someone else can. However, my own
experience indicates that "turbo" and "standard" provoke exactly the same
problem. You're right, I was lucky that the computer came on again; you can
just tell that it was touch and go. Overclocking manually from 200 to 201
completely eliminates the problem. Perhaps any overclocking, no matter how
small, automatically disengages the "turbo" setting without telling you
this. Or PAT is the problem and overclocking eliminates PAT -- I really
don't know. "Not particularly fast" is a subjective comment; have different
computers in the house, and considering how much the memory and processor
set me back, I expected more -- snap. On the positive side, I can open a
good number of heavy programs, and have them operating simultaneoulsy
without even the hint of a crash; the computer churns on. Is there a
benchmark for this?

The P4 uses a longer pipeline, dicing the processing steps up into
more simple primitives. This allows the clock rate to be raised.
But a longer pipeline is a liability if the pipe needs to be flushed,
like when an unexpected branch happens. You cannot expect a linear
speedup.

You can compare your performance to the data contained in here.
While Tom's makes lots of mistakes in reviews, the data is
better than nothing.

http://www.tomshardware.com/cpu/20030217/index.html

A more interesting source of info are SPEC benchmarks.

http://www.specbench.org/cpu2000/results/
http://www.specbench.org/cpu2000/results/cpu2000.html

Dell Precision WorkStation 410 (700 MHz, Pentium III processor) 1 307 --
Dell Precision WorkStation 420 (733 MHz PIII) 1 368 374
Intel Corporation Intel D850EMVR (2.8 GHz, Pentium 4 (533) ) 1 1032 1040
Intel Corporation Intel D875PBZ (2.80C GHz, Pentium 4 HT) 1 1166 1204

You can see the benefit in both cases, of increased FSB. Anything
that helps memory bandwidth couldn't hurt.

Paul

 

[Stan]

First of all thanks to everyone who answered my first posting about this
subject. The patience exhibited to the "stupid" questions of newcomers is
appreciated.
So I took the advice and set memory to 400mhz manually -- removing the AI
overclocking feature of my p4p800 board. All ok.
Decided then to stop overclocking. Apparently this enables the mysterious
PAT, and anyway I'm not sure why I overclock -- probably just to feel like
I'm getting something for nothing -- so I reset the CPU to 200 (2.8 P4 800
fsb). Computer never comes back on. Try AI "standard" setting. Same thing. I
remove "turbo" setting and computer works. In other words, if I overclock I
can keep "turbo" enabled and the computer seems quite stable. If I return to
the settings that reflect the actual hardware, the computer dies if "turbo"
is enabled. Something contradictory here, yes no? Basically I would like
some opinions on what the best performance settings are. Thanks.

Original message: Can anyone comment on these memory timings from the
program cpu-z? Are they
correct for the memory I have on this motherboard? I would just like to
know if I have the memory working correctly. I have a p4p800 mb, xp pro, 1
gbyte divided in two 512, pc3200 corsair twin memory cards. Bios settings:
MAM enabled, turbo enabled and overclocked 10% (2.8 mhz processor, 800 fsb)
by AI overclocking to 3079 mhz. Computer is stable, but not particularly
fast.

The program gives me:

Size: 1024 (correct)
Channels: dual
performance mode: disabled (WHY DISABLED?)
modules information: Corsair ddr-sdram pc3200
frequency: 146.7 (SHOULDN'T IT BE 400?)
cas latency: 2.5
ras to cas delay: 4 clocks
ras precharge: 4 clocks
cycle time: 8 clocks

My P4P800 settings running 4X256MB 333Mhz PC2700 Kingston
Value Ram (over-clocked to 400Mhz) are as follows:

Size: 1024 MBytes
Channels: Dual
Performance Mode: Enabled
Frequency: 200.5 MHz
FSBRAM: 1:1
CAS # Latency: 2.5
RAS# to CAS# Delay: 3 clocks
RAS# Precharge: 3 clocks
Cycle Time: 5 clocks

Rock-solid for the past 5 months or so - unless I enable Turbo mode
which immediately prevents the system from booting. I leave it in
Standard mode with no problems. MAM is enabled.

Stan

 

[gawderho]

Oh I had to laugh..... Jim,.... not at you but your first response, "Oh
Lucky You!"......

We all have been through it. And, the times it was the hardest to recover
the CMOS setup, was when I was fooling around with screwy TURBO.

Normally, I can get a CPR after (2) complete power off shutdowns.

Robert, this helped me set the DDR Ratios:

DDR400 = 1:1
DDR333 = 5:4
DDR266 = 3:2

1:1 - when FSB is 800MHz = 400MHz memory
5:4 - when FSB is 1000MHz = 400MHz memory
3:2 - when FSB is 1200MHz = 400MHz memory

Your settings are fine though. Your gettin it!

Like right now, my FSB is 1100MHz so I'm using the 3:2 Ratio.

gawderho

 

[gawderho]

Hey Robert,

Check your DMA box for your Hard Drive(s) in Device Manager or the 32 Bit
Disk Access in your BIOS in your Drive Settings.

Both of these were disabled for me and DMA enabled made a major performance
increase in my whole OS. It's really snappy now.

 

[robert]

Just curious about something.
Do I finally have it right?

The program CPU-Z says that Performance Mode is disabled. Are we talking
about the same setting on the p4p800 mb: turbo, standard, auto?
If it is the same setting, therefore, the bios says that it is enabled but
it's not, right?
It's not enabled, because the cpu is overclocked, right?
If I don't overclock, the "turbo" setting really, actually and truly goes
into effect, right?
And the computer never wakes up again, right?

 

[jaeger]

The program CPU-Z says that Performance Mode is disabled. Are we talking
about the same setting on the p4p800 mb: turbo, standard, auto?

No. Always leave that at standard. Performance Mode in CPUZ refers to
Performance Acceleration Technology(PAT), which on an 865PE Asus calls
Memory Acceleration Mode(MAM), because PAT is only supposed to be on
875P boards. MAM/PAT on a P4P800 is enabled through a BIOS hack that
Intel doesn't want or endorse.

 

[Darkfalz]

Size: 1024 (correct)

Channels: dual
performance mode: disabled (WHY DISABLED?)
modules information: Corsair ddr-sdram pc3200
frequency: 146.7 (SHOULDN'T IT BE 400?)
cas latency: 2.5
ras to cas delay: 4 clocks
ras precharge: 4 clocks
cycle time: 8 clocks

PAT gives the biggest increase in memory throughput, and like you said, it
automatically disables itself when overclocking on P4P800 chipsets (I hear
not on P4C800).

I think Performance Mode just tries some agressive RAM timings underneath
the SPD ratings, and that's why it's usually not working.

 

[Ed Jay]

PAT gives the biggest increase in memory throughput, and like you said, it
automatically disables itself when overclocking on P4P800 chipsets (I hear
not on P4C800).

I think Performance Mode just tries some agressive RAM timings underneath
the SPD ratings, and that's why it's usually not working.

Yup! 2,2,2,5.

Ed Jay (remove M to respond)

 

[Darkfalz]

Yup! 2,2,2,5.

Mine is SPD rated at 3,3,3,8 but I can reliably run it at 2.5,3,3,5.

However it doesn't seem to provide any increase in throughput, so I just
leave it at default.

 

[Ed Jay]

Mine is SPD rated at 3,3,3,8 but I can reliably run it at 2.5,3,3,5.

However it doesn't seem to provide any increase in throughput, so I just
leave it at default.

My memory is rated at 2,3,3,7. It seemed to run fine with Turbo set,
i.e., 2,2,2,5, but only up to its rated speed of 434MHz. Memory
bandwidth numbers were best (Sandra) at those settings, but after
reading about everyone else's instability problems with Turbo set, I
backed off. I'm achieving close to the same performance at 2,3,3,7
running the FSB up a bit (450).

Ed Jay (remove M to respond)

 

[Darkfalz]

My memory is rated at 2,3,3,7. It seemed to run fine with Turbo set,

i.e., 2,2,2,5, but only up to its rated speed of 434MHz. Memory
bandwidth numbers were best (Sandra) at those settings, but after
reading about everyone else's instability problems with Turbo set, I
backed off. I'm achieving close to the same performance at 2,3,3,7
running the FSB up a bit (450).

Increasinlg FSB turns off PAT for me, I'd check if it does the same for you.

 

[Ed Jay]

Increasinlg FSB turns off PAT for me, I'd check if it does the same for you.

According to CPU-z, it does for me too.

Ed Jay (remove M to respond)

 

[Darkfalz]

According to CPU-z, it does for me too.

Then you're better off leaving it clocked at default and enjoying the free
PAT performance boost.

 

[jaeger]

Then you're better off leaving it clocked at default and enjoying the free
PAT performance boost.

Not really, even a 5MHz boost in memory speed will give more performance
than PAT. Although in either case "more performance" means nothing more
than a small increase in pointless synthetic benchmarks.

 

[Ed Jay]

Then you're better off leaving it clocked at default and enjoying the free
PAT performance boost.

Nope. According to Sandra, PAT only gives a modicum of improvement. A
slight increase of the FSB clock does a lot more than PAT.

Ed Jay (remove M to respond)

 

[Darkfalz]

Not really, even a 5MHz boost in memory speed will give more performance

than PAT.

Not true at all.