Speed of SDRAM on P4B

GMinns · 12-17-2001, 11:06 PM

I have a P4B with P4 1.6MHz and 640k SDRAM (2x256 PC133 and 1x128 PC133).

To my understanding the FBS of the P4 is 100x4=400Mhz, is my RAM working at 133MHz or 100MHz ?.

When I run Sandra V.2001, it did not show me the speed of my RAM, how can I find out the speed the RAM is working at ?.

If the RAM is only working at 100 MHz, how can I speed it up to 133Mhz ?.

I see in the manual I could change the switchs to set the RAM speed to 100MHz or 133MHz, would this be the way to make my RAM run at 133MHz ?.

In the BIOS is a CPU/Memory Frequency Ratio, I can set it to AUTO, 1:1 or 3:4,

If it's set to 1:1 is the RAM working at 100MHz
If it's set tc 3:4 is the RAM working at 133Mhz (100/3x4=133)
What speed is the RAM at it's set to AUTO.

**k0NG0** · 12-18-2001, 07:45 AM

I'm not entirely sure, but a qualified guess would be that the RAM is set at the speed that's noted in the SPD [Serial Presence Detect] on the RAM sticks.
There's no risk in setting the ratio at 3:4 to get the 133MHz speed, so that would be an option to ensure that you're using the memory at the fastest speed.

-kONGO

StarTraveller · 12-18-2001, 07:56 AM

Just guessing, but wouldn't programs like CPUID and Sandra be able to tell the memory speed?

Maybe run a benchmark at different settings to confirm the faster one...

Bluztonemunkey · 12-18-2001, 11:49 PM

Great Questions GMinns, sorry I can't ansewer better, I'm on 1:1 with a FSB of 108, so I figure 108 memory speed. Also set to turbo 2, which seems to change memory to cas 2 2 2 . I'd like to know about the 3:4 setting, my free version of sandra does'nt have the memory benchmark. Hopefully someone here can help us!

Keri · 12-19-2001, 08:17 AM

My friend and I discussed this at length last night after I read this thread.

Technically it would have to be running at 100MHz! We can find no way the RAM could run at 133 with the FSB at 100MHZ (Quad Pumped).

This is two educated quesses but my vote says that the RAM is running at 100 & not 133.

**k0NG0** · 12-19-2001, 08:37 AM

From the datasheet of the i845 MCH.

I see no problem in running the memory at 133MHz while the bus is at 100MHz (QDR). If it could be done with VIA's 694x, I bet Intel can pull it off. And the second excerpt above tells me that the speed is indeed set via the SPD.

-kONGO

GMinns · 12-19-2001, 09:39 PM

Hi all, thank you for your input.

I have changed the CPU/Memory Ratio and got the following numbers from Sanda:

Auto = ALU 614, FPU 620
1:1 = ALU 452, FPU 454
3:4 = ALU 620, FPU 624

It looks like if i set it to AUTO the memory must be at 133Mhz.

Looking in the manual under CPU/Memory Ratio it states this field determines whether the memory clock frequency is set to be in sychronous or asychronous mode with respect to the system frequency.

If the CPU/Memory Radio is set to AUTO and it looks like the memory is at 133MHz would you not think that the External clock frequency would also be at 133MHz ?.

I have also run WCPUID and it shows the Internal clock frequency of 1614MHz but did show any External clock frequency or the clock multiplier.

I did run Sanda on my old MB and it did show the memory setting but dosn't show on the P4B.

If you know if any other programs that show memory setting or the clock frequency please let me know.

The next part if my question is what is this doing to me PCI and AGP frequency, if any thing at all and how do i control the Bus frequency if i up the CPU frequency or do i need to

**k0NG0** · 12-20-2001, 03:45 AM

The FSB is still only 100MHz (QDR) since the AUTO setting for the memory is the 3:4 ratio (FSB:MEMORY), and since the CPU is only rated to run at 400MHz, the MCH (Memory Controller Hub) or BIOS will detect that and use that setting.
In the future, with the 533MHz FSB Northwoods, memory will run synchronously (1:1) though.

The AGP and PCI buses run at a fraction of the FSB, usually the fractions are 2/3 and 1/3 (AGP, PCI) when the FSB is between 100 and 132MHz, and the new dividers (1/2 and 1/4) kick in when the FSB is 133MHz or over.

This means that you will automatically overclock the AGP and PCI bus when you increase the FSB to the CPU. Some PCI and AGP cards are sensitive to overclocking, and may work bad when overclocked, but usually increases in FSB up to 112MHz work, this is not certain though. When you overclock you have to keep increasing the FSB in small steps and run some form of software that stresses the system to see that things are stable. If they're not, you can increase the voltage to the CPU in small steps also. I hear that the P4 overclocks quite nice with default voltage though, so I think it's safest to stay with that and just increase the FSB.
Be advised though, that you have adequate cooling when overclocking, since the CPU will put out more heat.

-kONGO

12-17-2001, 11:06 PM	#1
GMinns Registered User Join Date: Dec 2001 Location: Canada Posts: 6	Speed of SDRAM on P4B I have a P4B with P4 1.6MHz and 640k SDRAM (2x256 PC133 and 1x128 PC133). To my understanding the FBS of the P4 is 100x4=400Mhz, is my RAM working at 133MHz or 100MHz ?. When I run Sandra V.2001, it did not show me the speed of my RAM, how can I find out the speed the RAM is working at ?. If the RAM is only working at 100 MHz, how can I speed it up to 133Mhz ?. I see in the manual I could change the switchs to set the RAM speed to 100MHz or 133MHz, would this be the way to make my RAM run at 133MHz ?. In the BIOS is a CPU/Memory Frequency Ratio, I can set it to AUTO, 1:1 or 3:4, If it's set to 1:1 is the RAM working at 100MHz If it's set tc 3:4 is the RAM working at 133Mhz (100/3x4=133) What speed is the RAM at it's set to AUTO. __________________ Asus P4C800-E BIOS V.1008 P4 3.06MHz Windows XP Home ATI AIW 9600 DDR 512Kx2 CD-RW Sony CRX-1611 DVD-ROM Pioneer DVD-104 LCD Monitor NEC 1700V WD 120MB IDE x 2 Raid(1)
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12-18-2001, 07:45 AM	#2
k0NG0 Remembering TQ Join Date: Mar 2001 Location: Sweden Posts: 13,638	I'm not entirely sure, but a qualified guess would be that the RAM is set at the speed that's noted in the SPD [Serial Presence Detect] on the RAM sticks. There's no risk in setting the ratio at 3:4 to get the 133MHz speed, so that would be an option to ensure that you're using the memory at the fastest speed. -kONGO
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12-18-2001, 07:56 AM	#3
StarTraveller Retired Modder Join Date: Apr 2001 Location: Cloud Nine Posts: 6,468	Just guessing, but wouldn't programs like CPUID and Sandra be able to tell the memory speed? Maybe run a benchmark at different settings to confirm the faster one... __________________ StarTraveller.net - see Computers for current setup! Well, it used to be current... Right now, my primary computer is a ThinkPad T43p 2668-H7U upgraded to 2 GB RAM Motto: If it is worth doing then it is worth doing right! Caution: The light at the end of a tunnel may be an oncoming train...
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12-18-2001, 11:49 PM	#4
Bluztonemunkey Registered User Join Date: Dec 2001 Location: INDY Posts: 24	Great Questions GMinns, sorry I can't ansewer better, I'm on 1:1 with a FSB of 108, so I figure 108 memory speed. Also set to turbo 2, which seems to change memory to cas 2 2 2 . I'd like to know about the 3:4 setting, my free version of sandra does'nt have the memory benchmark. Hopefully someone here can help us!
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12-19-2001, 08:17 AM	#5
Keri Waiting for HL2 Ep:3 Join Date: Feb 2001 Posts: 2,996	My friend and I discussed this at length last night after I read this thread. Technically it would have to be running at 100MHz! We can find no way the RAM could run at 133 with the FSB at 100MHZ (Quad Pumped). This is two educated quesses but my vote says that the RAM is running at 100 & not 133. __________________ Intel Core 2 Duo E6550 Monsoon II TEC CPU Cooling System Asus P5N32-E SLI Plus 2X1GB Gskill DDR2 800 Lian-Li PC-V2000B OCZ 520W Modstream Asus DRW-1814BLT SATA Dual Layer DVD Burner 1 X Western Digital 320G SATA II 2 X Maxtor 250G SATA I 1 X Western Digital 250G External USB 2.0 MSI NX8600GTS 256MB PCI-E Samsung Syncmaster 20" 205BW Widescreen TFT Windows Vista Ultimate Edition 32bit 2GB Cruzer Flash Drive (Ready Boost) Logitech X-540 5.1 Surround System Logitech Cordless Keyboard Logitech MX1000 Laser Mouse
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12-19-2001, 08:37 AM	#6
k0NG0 Remembering TQ Join Date: Mar 2001 Location: Sweden Posts: 13,638	From the datasheet of the i845 MCH. I see no problem in running the memory at 133MHz while the bus is at 100MHz (QDR). If it could be done with VIA's 694x, I bet Intel can pull it off. And the second excerpt above tells me that the speed is indeed set via the SPD. -kONGO
(Offline)

12-19-2001, 09:39 PM	#7
GMinns Registered User Join Date: Dec 2001 Location: Canada Posts: 6	Speed of SDRAM on P4B Hi all, thank you for your input. I have changed the CPU/Memory Ratio and got the following numbers from Sanda: Auto = ALU 614, FPU 620 1:1 = ALU 452, FPU 454 3:4 = ALU 620, FPU 624 It looks like if i set it to AUTO the memory must be at 133Mhz. Looking in the manual under CPU/Memory Ratio it states this field determines whether the memory clock frequency is set to be in sychronous or asychronous mode with respect to the system frequency. If the CPU/Memory Radio is set to AUTO and it looks like the memory is at 133MHz would you not think that the External clock frequency would also be at 133MHz ?. I have also run WCPUID and it shows the Internal clock frequency of 1614MHz but did show any External clock frequency or the clock multiplier. I did run Sanda on my old MB and it did show the memory setting but dosn't show on the P4B. If you know if any other programs that show memory setting or the clock frequency please let me know. The next part if my question is what is this doing to me PCI and AGP frequency, if any thing at all and how do i control the Bus frequency if i up the CPU frequency or do i need to __________________ Asus P4C800-E BIOS V.1008 P4 3.06MHz Windows XP Home ATI AIW 9600 DDR 512Kx2 CD-RW Sony CRX-1611 DVD-ROM Pioneer DVD-104 LCD Monitor NEC 1700V WD 120MB IDE x 2 Raid(1)
(Offline)

12-20-2001, 03:45 AM	#8
k0NG0 Remembering TQ Join Date: Mar 2001 Location: Sweden Posts: 13,638	The FSB is still only 100MHz (QDR) since the AUTO setting for the memory is the 3:4 ratio (FSB:MEMORY), and since the CPU is only rated to run at 400MHz, the MCH (Memory Controller Hub) or BIOS will detect that and use that setting. In the future, with the 533MHz FSB Northwoods, memory will run synchronously (1:1) though. The AGP and PCI buses run at a fraction of the FSB, usually the fractions are 2/3 and 1/3 (AGP, PCI) when the FSB is between 100 and 132MHz, and the new dividers (1/2 and 1/4) kick in when the FSB is 133MHz or over. This means that you will automatically overclock the AGP and PCI bus when you increase the FSB to the CPU. Some PCI and AGP cards are sensitive to overclocking, and may work bad when overclocked, but usually increases in FSB up to 112MHz work, this is not certain though. When you overclock you have to keep increasing the FSB in small steps and run some form of software that stresses the system to see that things are stable. If they're not, you can increase the voltage to the CPU in small steps also. I hear that the P4 overclocks quite nice with default voltage though, so I think it's safest to stay with that and just increase the FSB. Be advised though, that you have adequate cooling when overclocking, since the CPU will put out more heat. -kONGO
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