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Ovrclocking P4/2666 w/RAMBUS

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Anonymous
a b à CPUs
a b V Motherboard
a b K Overclocking
April 27, 2002 9:07:51 AM

According to the article<b>Behind The Silicon Curtain:
Exclusive Test Of The P4/2666 With 533 MHz Rambus</b> (http://www6.tomshardware.com/cpu/02q1/020225/p42666-04....) it states:

"In order to overclock the latest Pentium 4, the CPU core voltage needs to be significantly increased. All P4s with the Northwood core are factory-set to 1.5 Volt - but this is not enough for a big increase in clock speed. Most of the motherboards allow for voltage adjustment between 1.05 Volt and 1.65 Volt maximum - the absolute limit lies at 1.85 Volt."

I have noted that this "absolute" limit seems to be exceeded by the <b>Abit SD7-533</b> motherboard. The article<b>SiS Kicks Off: 10 Motherboards With The 645 Chipset and DDR333</b> states on page (http://www6.tomshardware.com/mainboard/02q2/020403/sis6...) that:

"Soft Menu is the name for Abit's CPU configuration menu within Award BIOS. Here, you can make settings for all of the relevant CPU parameters, such as FSB speed, CPU multiplier and the CPU core voltage. Unfortunately, Intel has kept the multiplier locked for years, and this cannot be changed. Also, FSB speeds of over 145 MHz do not run stably anymore. However, the most important aspect here should be the huge spectrum of available CPU core voltages: you can choose from voltages ranging between 1.1 and 2.2 V (in 0.025 V increments)."

My question is, in the first article a pull down resister is used to enable higher voltages to the CPU, up to 2.05 Volt. Am I correct to think that the Abit board remedys the need for a pull down resistor and also increases the max voltage above 2.05 to 2.2 without soldering to the board? Or...am I missing something about incompatibility or something between these two articles?

With RAMBUS and DDR-SDAM being close in price and RAMBUS having a higher bandwidth will this board work with the new P-4 chip when its released?

Would this seem to make sense? Are DDR-SDRAM and RAMBUS memory motherboard exclusive, or interchangable?

I think I know, but I feel that I'm missing something, other than the CPU isn't released yet(P4/2666). Any help?

Thanx, TJ
April 29, 2002 7:14:14 PM

The BD7 will not need a resistor soldered on in order to reach it's maximum voltage.

DDR and RDRAM require different sockets and chipsets, the TH7II is the board I would recommend, as well as Samsung PC800.

<font color=blue>If you don't buy Windows, then the terrorists have already won!</font color=blue> - Microsoft
April 29, 2002 10:49:42 PM

hey all, im new :) 

right, ive been reading THG for sometime now, and have been thinking things over in my head, but now its time for me to jump in and play.

right, im still confused on this "resistor" business, say for example i have just got myslef a new:

P4/2666 (on order)
ABIT TH7II
SAMSUNG 512MB RAMBUS 800Mhz ECC RIMM (4-sticks - 2gb)
INNOVATEK KIT

Can i just crank the CPU core voltage up to 1.85v or do i need to get my soldering iron out to pin 7 on the regulator module? If this is the case and i do need to get messy with the solder, then i should be fine... but i am really confused with the resistors, do i need to do this, is there anyway round... and if i do need to do it, can you give me some pointers on ohmage (heheh im sure thats not right) and how to go about setting it all up

Any help would be appreciated as im kind of new to overclocking the p4

- rob
April 29, 2002 10:55:08 PM

I'd be careful with voltage that high! The P4 runs at 1.5V at default. 1.85V may hurt it without proper cooling. Also, where did you get a P4 2.66GHz? I thought the fastest currently available is the P4 2.4GHz.

:wink: <b><i>"A penny saved is a penny earned!"</i></b> :wink:
April 29, 2002 11:18:49 PM

hey man,

the p4 is currently on order from my local computer store, they dont expect it in till atleast mid may probably later,

I will be using the Innovatek water cooler to keep the temp as low as i can manage.

Any advice on my last post?

-rob
April 29, 2002 11:31:38 PM

ok.. thinking about it now..

basically if i have the above kit, do i need to change anything on the motherboard to be able to overclock the p4/2666 (when i get it) i.e. do i need to solder anything or add resitors?

I know what needs changing in the BIOS and i dont have a problem with that.... just the additional hardware side im a little confuseses

rob
April 29, 2002 11:32:55 PM

Something else I've noticed with RDRAM is that you need to have a dummy stick in the RAM slots that don't have any memory. I learned this with a Counselor's P4 Gateway computer. I was trouble shooting it and once I figured out how to access the BIOS to enable the full memory test, found out that at 68MB (128MB total), it would fail. Of course I just tried to remove one stick and narrow it down and with an open slot, the darn thing wouldn't boot. Oh well, at least I got the problem figured out. Hope she went and got a new stick for me to install and get the system back up and running.

GearJammer

Believe only half of what you read and none of what you hear! Unless it's in THGC forum.
April 30, 2002 3:51:24 AM

I haven't done any physical modifications on my board and my 1.6A hums along nicely at 2.5.

Yes, you have to use Continuity RIMMs (CRIMMs) to tell the motherboard that those slots are empty.

<font color=blue>If you don't buy Windows, then the terrorists have already won!</font color=blue> - Microsoft
April 30, 2002 4:51:23 AM

So that's what those things are called. The instructor and I have just been calling them terminators (like the ones used on SCSI chains). I wonder if Gateway would donate a couple of those to my school in case another P4 computer comes in and we need to troubleshoot RAM problems. I'll have to check with the local store and find out.

Believe only half of what you read and none of what you hear! Unless it's in THGC forum.
April 30, 2002 5:35:54 PM

Every motherboard comes with two, and I haven't seen any OEMs that use all four RAM slots, so I don't think you would need any extra CRIMMs.

By the way, the reason that those are needed is because RDRAM is serial. The signal path has to travel through all slots before going back to the memory controller. For this reason, filling all 4 slots with RDRAM adds to the latency (though the amount of change is unkown). Basically, the CRIMMs just tell the signal "Nothing to see here, move along".

<font color=blue>If you don't buy Windows, then the terrorists have already won!</font color=blue> - Microsoft
May 2, 2002 3:06:45 AM

By the way, the reason that those are needed is because RDRAM is serial. The signal path has to travel through all slots before going back to the memory controller. For this reason, filling all 4 slots with RDRAM adds to the latency (though the amount of change is unkown). Basically, the CRIMMs just tell the signal "Nothing to see here, move along".


Except for Rimm 4200 signal stop at the module on-board teminator (not the good typing i must go read again the PDF of Rimm 4200) The signal dont return to the MCH but at the mobo.I just i remember every thing right.

cheap, cheap. Think cheap, and you'll always be cheap.AMD version of semi conducteur industrie
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