General Overclocking Questions for 8RDA+ owners

[Ilmater]

I finally got my new SCSI card last night (LSI Logic is worthless, Adaptec rules!!!) and got everything going on my 8RDA+ system with a T-Bred B 1700+. Well, I was able to run stably at 2100MHz with a 1.75V Vcore and a 200MHz FSB for one run of 3DMark 2001, but I can't duplicate it. I finally went to 190MHz FSB and 10.5 multiplier, and when I left home (running Prime 95 and 12 loops of 3DMark right now) it was going smoothly.

I got a board with 1.58V Vdd, which I thought would be enough for a 200MHz+ FSB, but apparently I was wrong. I'd love to see where I can take this thing, so I have a few questions.

First, I'd like to do the Vdd mod, but I'm not sure if I want to take the Vdd to 1.84V or 1.76V. These are my two options with 680ohm and 1000ohm resistors, respectively. What kind of results has anyone gotten with these voltages? How much damage will I do to my NB by running at 1.84V? I have a COrb on my NB and the old passive NB heatsink on the SB.

Secondly (remember, this is my first time overclocking), what kind of temperatures should I shoot for with my CPU? When I set it to 1.75 Vcore and 2.2GHz, after it locked up and I rebooted, my BIOS temps were 41C. Is that too hot? Can I up the voltage more? I've got a Swiftech MCX-462+ with a 92mm Panaflo H1A on it.

 

[syberscott]

For the Vdd mod why not put a plug in instead of soldering in a resistor. Then you can change the resistance if you like. Electronic stores often have boxes of used wires with plugs for cheap. The biggest problem with the NB is not your cooling solution, but the fact that it is concaved and doesn't make good heatsink contact. Either lap it or use more AS3 than you normally would.

With your cooling setup I'm pretty sure that you could handle up to 1.85 Vcore. Just keep an eye on the temps; 41c is fine.

 

[Ilmater]

Originally posted by: syberscott
For the Vdd mod why not put a plug in instead of soldering in a resistor. Then you can change the resistance if you like. Electronic stores often have boxes of used wires with plugs for cheap.

By plugs, do you mean variable resistors? I'm not sure how you mean to attach them without soldering something.

The biggest problem with the NB is not your cooling solution, but the fact that it is concaved and doesn't make good heatsink contact. Either lap it or use more AS3 than you normally would.

Not a problem. Both were lapped thoroughly and AS3 applied. However, I would like to be able to check the temperature of my NB. Is there a way to do this?

With your cooling setup I'm pretty sure that you could handle up to 1.85 Vcore. Just keep an eye on the temps; 41c is fine.

I know 41C is OK, but how high CAN I go? Mind you, this is continuous, stable operation I'm going for. I don't want to run at 80C for a day or two, I want to be able to run at whatever temps with whatever voltage for quite some time.

 

[syberscott]

By plugs I mean the female plugs that are used to attach to the male ends on your motherboard (you do know the difference between male and female right? sorry, couldn't resist) They are used for your front case LEDs, case speaker, etc. You will notice that you can plug a resistor right into one of these plugs. By doing it this way you can have a variable resistance (by putting it different valued resistors) without the danger of turning the variable resistor too low and blowing your board. I hope I clarified this; I've reread it and I don't seem to be explaining it very well.

As far as temps go, I have one of those laser temperature guns. It's great and I think you can get them pretty cheap now.

I hate recommending maximum temperatures because every board is different. I like to stay under 50C when under full load, just to be on the safe side.

 

[Killrose]

I'd think the variable "pot" resistor would be the way to go. See if you can get one with the range you desire to work within.

 

[syberscott]

Originally posted by: Killrose
I'd think the variable "pot" resistor would be the way to go. See if you can get one with the range you desire to work within.

Pots start at zero ohms. If you accidentally start up your motherboard with too low a resistance...POOF. And you can't check the resistance once it's soldered in. Pots can be troublesome, I would not trust my computer to one. If you really want to go that route, at least solder a 680 ohm resistor in series with it.

 

[paco83]

if you have a 1k ohm variable resistor and put a 500 ohm normal resitor in series with it, and another 500 ohm resitor in parallel with it (the VR), you'll essentially have a 500-1000 ohm variable resitor

 

[wicktron]

Originally posted by: paco83
if you have a 1k ohm variable resistor and put a 500 ohm normal resitor in series with it, and another 500 ohm resitor in parallel with it (the VR), you'll essentially have a 500-1000 ohm variable resitor

I'm not down with VR's because they don't provide as stable of a voltage as a true-rated resistor.

 

[k1114]

Originally posted by: wixt0r

Originally posted by: paco83
if you have a 1k ohm variable resistor and put a 500 ohm normal resitor in series with it, and another 500 ohm resitor in parallel with it (the VR), you'll essentially have a 500-1000 ohm variable resitor

I'm not down with VR's because they don't provide as stable of a voltage as a true-rated resistor.

That and most variable resistors (unless you get an expensive one) lose accuracy with every turn.

 

[syberscott]

To the last 2 posts. BINGO