EpoX 8RDA+, how much Vdd, low performance.

[***Deimos***]

I have an EPoX 8RDA+. Stock Vdd is 1.56-1.58V. Since I sold the OCZ 3500EL, I only have 1 stick of 512MB XMS3500. Running my XP2500+ @10x200 with CPU at "Optimal" and memory at 2-2-2-11 gives 56 sec in SuperPi 1M. Setting CPU to "Aggressive" yields 55sec. Not bad but a bit less than what others are getting at about the same frequency... but probably due to lack of DC right?

I did the vdd mod with 2K 30 turn trimmer. I raised the Vdd to 2.05V and fsb all the way up to 238, and memory at 238 @ 2.5-3-3-8 2.9V. 2380Mhz and SuperPi=47sec

Isn't this a bit slow?
http://www.vr-zone.com/reviews/EPoX/8RDA+/page6.htm
they get 49sec at 10x200... other sites get about 48-51 sec for the same CPU speed... am i missing something.

Also, when I run sandra arithmetic CPU test, the int scores are 2.5-3% lower than the ones indicated for stock, regardless of fsb, mem setting etc... makes sense.. but all same model CPU's being equal shouldn't I get the identical scores... (ex. sandra XP2500 score = my XP2500 score)

[`schr0et]

XMS3500 = BH-5

Set timing to 2-2-2-11, and do a VDimm mod if you want.

Also runnning 2x 256 sticks dual channel is faster than running 2x 512 sticks dual channel and will let you oc higher.

Never pay direct attention to direct benchmarks between the bench makr and end user there are too many hardware and software differences to evenly compare.

[STEvil]

2x256 DC is only faster than 2x512 DC if you are running higher mhz for the 2x256.

That said, try a different bios. I'm on the 4212 right now.. its nice. 1.9vdd for 232 24/7 stable.

Have a bunch of mods planned for this thing.. and will be running a minimum of 2.1vdd soon, heh.

[sexsymbol]

Remenber to cool the vreg chip and don´t go above 2.1 vdd. The northbridge can handle it but the vreg chip no. My vreg chip after two hours at 2.2vdd with heatsink on top and fan blowing completely burned. I don´t recommend you to do the vdimm mod. It is difficult and I think doens´t work properly, well it works properly but it is difficult to adjust both values to work correctly. Also my 8rda+ and my BH5 had a bad relationship, no matter what FSB impossible to run cas2. Haven´t tried the latest bios, but with the first ones no good.

[STEvil]

Mine isnt even warm to the touch at 1.9.. will see what it does at 2.1+

[dobby]

the vreg chip you talk about , is that the one next to the socket or next to the AGP-slot ??

[sexsymbol]

The one where you do the vdd mod. Between the agp slot and the memory banks. The chip beside also gets toasty. My experience was with an 8rda+ v1.1. 1.9v its pretty safe, I think the limit for 24/7 is 2.1. At 2.2 as I said before only lasted for 2 hours.

[saaya]

i know a guy who was running 2.5v for a couple of days with the default nb heatsink!!! then it died... i think 2.3v+ is ok if you have some good nb cooling.

[***Deimos***]

I thought I was crazy with 2.05V... and I didn't dare do that without removing the default NB (<40g can't be good), and replace with Duron/Athlon ChromeOrb.. remember those? I had to smash off the Socket 462 clip and some other plates... and then spend about hour sanding the bottom and the nForce2, and then a long wire through the holes and twist tie and I'm done!!

However, there is so little space, that the ChromeOrb is pressed agains the capacitor by the AGP slot and the CPU HS (touching both). What typically happens is, if the CPU HS gets hot, so does the NB HS.... I installed a small dinky fan for serious fsb overclocking, but I think it's not worth it... I accepted the fact that my NB stepping is a dud.

[sexsymbol]

Originally posted by saaya
i know a guy who was running 2.5v for a couple of days with the default nb heatsink!!! then it died... i think 2.3v+ is ok if you have some good nb cooling.

Thats amazing!! My mobo was 5 months old and in that period suffered really heavy overclock, maybee my vreg chip died little by little. The northbridge is amazing how much vdd you can feed, I was using watercooling on my northbridge but I think with a crystal orb is enough. If you plan to use the mobo for long time my personal recomendation is not to go above 2.1v (Don´t get angry with me saaya ). If you want to go higher get an 80w pelt on top of the northbridge instead of pumping higher vdd.

[saaya]

well yeah if you want it to last dont go over 2.1v, but if you wanna push the board to the max you can go as high as 2.3v or more with good cooling. if it helps! because on most boards it doesnt help... a1 a2 and a3 nb's love vdd, the new c1 stepping doesnt care about vdd anymore.

just think about how long yiou will use the board.

[***Deimos***]

saaya: I have the older a2 stepping... and although vdd helps it has diminishing returns... the first 0.1V will give you a big boost, but by the time you get to 2.0V, anymore voltage will only give you 1 or 2 extra fsb if any at all.

Sometimes when I'm pushing 2.0V through my NB just to get to 233Mhz, I like to pretend that I have a c1 stepping chipset running at the same fsb... stock NB hs, no extra fans anywhere, no vdd mod for extra voltage. Then again, modding is pretty fun.

[sexsymbol]

Try some heatsinks in the mosfets. In my case they were really usefull.

[***Deimos***]

Will do:

Otherwise I am getting the DFI NF2 Ultra Infinity..
just read a review where they got it up to 240+ (quite easily), and since I am planing to mod it, I would be very satisfied with 250.

Can some-one please confirm that the BIOS supports NB chipset adjustment to 1.8V (which I will mod anyway), Vcore up to 2.0V (which I will mod anyway) and Vdimm up to 3.2V (which I will mod anyway).. thanks

http://www.dfi.com.tw/Product/xx_pro...RODUCT_ID=2141

[STEvil]

Its been confirmed many times before.

[***Deimos***]

heatsinks on mosfets (those field effect transistors that act as voltage regulators in the upper left corner), 2 80mm fans blowing at that area, the "regular" chrome orb on NB, with 60mm fan setup, and 2.15V on NB(vdd)... in the BIOS the voltage number turned red, so I didn't go further. I also disabled ACPI since I heard that helps (not sure if supposed to be APCI.. always confuse the 2)... and finally I was able to SuperPi as 239 (2.5-3-3-11). 240 no go. 3-4-4-11 timings just cause it to reboot immediately after getting into windows (which CAS2.5 timings dont do). ALthough I have been repeatedly told that this memory is BH5 since it is Corsiar XMS3500, it can't even hold 220 stable... all this at 2.9V.. th max on this board. I would have to cut traces on mobo to feed more voltage.. but in my opinion waste of time, if I can just buy a DFI which could supply more voltage.

I also tried to get 240 using 83%, 80% and 66% memory multipliers and CAS2.5 timings, but no POST... won't work over 220Mhz with such multipliers. I also tried the 120%, and same thing.. wont work over 220Mhz. Only 100% allows me to get to 240... but SuperPi fails after half a minute only.