DFI using 5v rail for ram not 24/7 stable?

**Lifthanger** · 03-25-2005, 05:20 AM

on my board this spot is on the upper edge of the board. It's hot enough to burn your finger. In memtest only of course.. gaming and folding doesn't get nearly as hot.
I don't mind, because my NF7-S was just as hot around the vdimm circuit below the memory banks.
Maybe I'll try to rearrange the cooling, but I don't think ~80C (maybe more like 70C and memtest only) could damage a PCB in the long run.

**Eversor** · 03-25-2005, 05:02 PM

Originally Posted by EMC2

--- Eversor ---

Where specifically are you getting this hot spot on your MB, in the area of Q60 or over by D8 or ???

Q62/61, but lower, closing in to the mosfets.

I didn´t tried 5v when running like gaming or prime, may do so, and if it´s not too hot, my consider giving my bh-5 3.5-3.6v for 24/7.

**Jasonxxx** · 03-25-2005, 06:58 PM

I would think that when using the 5v rail to supply voltage to the memory that the higher the voltage to the memory, the less stress it would put on the mosfets...?

Can anyone confirm that you can indeed adjust your 3.3v rail on your power supply up to say ~3.5v and then just select say ~3.4v or ~3.5v for the memory in the bios and it be just fine?

Can you actually obtain the same voltage as the powersupply is suppling the mosfet? Meaning if you adjust your p.s. 3.3v line up to 3.5v can you actually supply 3.5v to your memory by selecting 3.5v in the bios?

**S0nic** · 03-25-2005, 07:07 PM

I'm would also like to see someone confim that, I'm expecting to receive my RAM on wednesday so if no one confirms this by then I will..

**bachus_anonym** · 03-25-2005, 07:41 PM

Originally Posted by Jasonxxx

I would think that when using the 5v rail to supply voltage to the memory that the higher the voltage to the memory, the less stress it would put on the mosfets...?

Can anyone confirm that you can indeed adjust your 3.3v rail on your power supply up to say ~3.5v and then just select say ~3.4v or ~3.5v for the memory in the bios and it be just fine?

Can you actually obtain the same voltage as the powersupply is suppling the mosfet? Meaning if you adjust your p.s. 3.3v line up to 3.5v can you actually supply 3.5v to your memory by selecting 3.5v in the bios?

no you cannot... option for vdimm above 3.1v show up in BIOS only after you switch jumper to 5v supply. in other words, with jumper in 3.3v position options are just not there... invisible... not existent... not available... gone...

**Jasonxxx** · 03-25-2005, 08:23 PM

thank you, that definately confirms it

**fareastgq** · 03-25-2005, 08:31 PM

You guys are worrying too much, I have literally used the 5 volt setting non stop for a month, I don't turn my comp off because I don't pay for electricity, but I do pay for my 3MB connection, so I download anime when I am at work, the board is fine :P If it dies within stock parameters and you cooled it properly, stop worrying :P Btw, when I run 2.8 volts or less, I don't cool the top right sink, when I run 2.9+, I do, also, in my experience, the 5 volt setting is more stable for a hardy OC than the 3.3 setting.

**EMC2** · 03-25-2005, 10:51 PM

Originally Posted by Eversor

Q62/61, but lower, closing in to the mosfets.

I didn´t tried 5v when running like gaming or prime, may do so, and if it´s not too hot, my consider giving my bh-5 3.5-3.6v for 24/7.

Those are the Vmem FETs

The copper plane under them acts as a HS (tab of package soldered to MB) and the MB dissapates more than the finned HS on top. No worries there... that's why you want your fan blowing from the "top edge" or better the "right edge" of the board across the MB surface, not from directly above the HS

--- Jason ---

You can get within 150mV of the rail safely (set in BIOS 0.2V less than rail). Regarding options in BIOS with 3.3V rail... it has been done... but many have no problems using the 5V rail.

**Skratch** · 03-26-2005, 09:20 AM

I dont know what dfi was thinking with the 5v jumpers.There is no way you can run this board stable that way.

I just tried the 5v again but this time with a temp probe.

with the jumper at 3v I can run my bh5 at 243 Tight timings at 3.2v and that mosfet stays at 84 F benching for over an hour (closed case).

Now with the jumper at 5v I can run my ram @250 tight timings @3.3v but get this the mosfets after 3 min of memtest hit 160 d F with open case and fans blowing on them.

can someone mod the bios to get at least 3.3v with out changing the jumper.

**DarkManX_BG** · 03-26-2005, 09:38 AM

160F (70C) is not that much, considering that the stuff there is supposed to take 105C...

**Skratch** · 03-26-2005, 09:56 AM

Originally Posted by DarkManX_BG

160F (70C) is not that much, considering that the stuff there is supposed to take 105C...

Lets see to go from 3.2volts on the ram to 3.3 I got a 60F increase.That was with open case with fans and only 3 min.

I tried for 3.4volts but the board would shut it self down before it could post.

**mdzcpa** · 03-26-2005, 10:04 AM

Originally Posted by Skratch

I dont know what dfi was thinking with the 5v jumpers.There is no way you can run this board stable that way.

Sure it can. I ran my for weeks at 3.4v 24/7.

So the area gets a bit warm...so what...just add a small fan

**Skratch** · 03-26-2005, 10:07 AM

Originally Posted by mdzcpa

Sure it can. I ran my for about 4 weeks at 3.4v 24/7.

So the area gets a bit warm...so what...just add a small fan

Mine shuts down after like ten min,thats why I said its not stable.

**mdzcpa** · 03-26-2005, 10:14 AM

What do you mean "shutsdown"?

Crashes? Reboots? BSODs?

Its likely something specific to your hardware....like your memory not liking that much voltage or the timings you are running. It can be a number of things. You hafta find the sweet spot. If its your memory that just doesn't like the voltage perhaps the jumper isn't for you. But as far as stability of the power supply using the jupmer...its pretty darn good. Someone recommended that I test the sag with a multimeter which I did. I was shocked to see a very stable voltage coming off the 5v jumper set up.

**Skratch** · 03-26-2005, 10:30 AM

Originally Posted by mdzcpa

What do you mean "shutsdown"?

Crashes? Reboots? BSODs?

Its likely something specific to your hardware....like your memory not liking that much voltage or the timings you are running. It can be a number of things. You hafta find the sweet spot. If its your memory that just doesn't like the voltage perhaps the jumper isn't for you. But as far as stability of the power supply using the jupmer...its pretty darn good. Someone recommended that I test the sag with a multimeter which I did. I was shocked to see a very stable voltage coming off the 5v jumper set up.

It just shuts off completely.It might be my psu.I have a 500watt xconnect.My ram loves the volts but the system just shuts down like a min after booting.

**fareastgq** · 03-26-2005, 11:41 AM

Originally Posted by Skratch

It just shuts off completely.It might be my psu.I have a 500watt xconnect.My ram loves the volts but the system just shuts down like a min after booting.

You should test with a known good psu and brand. The Ultra psu's are pretty light weight compared to alot of the other psu's I've seen (I'm speaking literally). When I say light, I'm comparing them to my pcp&c 510 deluxe, fortron 350 and 400, ocz modstream, even a thermaltake 420 silent purepower was heavier. I was actually suprised the ultra was so light for a 500w psu. This is in no way any means to gauge really how a psu performs, but most of the time weight & quality go hand in hand. Again, they run fine stock, but I don't think I would expect too much out of them.

**Revv23** · 03-27-2005, 03:24 PM

i would take a fortron 350 over a 500w ultra any day.

**Eversor** · 03-28-2005, 06:22 AM

Originally Posted by Jasonxxx

I would think that when using the 5v rail to supply voltage to the memory that the higher the voltage to the memory, the less stress it would put on the mosfets...?

Can anyone confirm that you can indeed adjust your 3.3v rail on your power supply up to say ~3.5v and then just select say ~3.4v or ~3.5v for the memory in the bios and it be just fine?

Can you actually obtain the same voltage as the powersupply is suppling the mosfet? Meaning if you adjust your p.s. 3.3v line up to 3.5v can you actually supply 3.5v to your memory by selecting 3.5v in the bios?

What you can, is do vdimm = 3.3v and then adjust the psu rail for more than 3.3v. I did the mod and am now running 3.3v to the dimms right from the psu´s rail.

**Jasonhk** · 03-28-2005, 06:27 AM

How do you do that mod details please

**Lifthanger** · 03-28-2005, 07:08 AM

I can't even get 210MHz stable with Twinmos SP running 3.2V from the 3.3V rail, while I can do 230MHz at 3.2V and 250MHz at 3.3V when running from the 5V rail.

Did someone else experience this problems?

It seems as if the 3.3V rail can't deliver that clean current than the 5V rail.

**Radelon** · 03-28-2005, 08:38 AM

I just tested this over the weekend. I had been using the 5v for my tccd @ 2.6v DDR590 and it was 100% stable. So after reading this thread I switched to the 3.3v and now it's not stable at DDR560 with all exact same settings in bios. So for me, the 5v route is way more stable. I'll switch back to 5v tonight and see if stability comes back. I mean who knows, it could be another Winny with IMC goin' bad.

**pershoot** · 03-28-2005, 08:49 AM

yup +5 is more stable in regards to voltage supply then +3 is. however, be warned, that you should not run below 3.3 while on +5. as an example, i was testing on +5 and went to 3.1 while #5'in it in memtest. after a few passes, the caps in the dimm area started hissing/making a repeated charge noise from this (which was loud, hehe).

**blackjok3r** · 03-28-2005, 06:01 PM

Mine was fine on the 5v for a while. But it ot waay too hot. I need a fan thats all. With a fan on the right corner angled across the board, it would cool the mosfet and the pcb area Eversor was talking about.

**S0nic** · 04-03-2005, 11:52 AM

well I finally got my VX and did some testing, I have a 80mm fan directly above the mosfets area and I find the at full load it heats up so much it's kinda scary, couldn't leave it running overnight while I was sleeping because I was afraid it would start a fire or something, I tried using the 3.3V line but that won't work, max I can get out of it is 3.2V which is not enough for my VX, do the newer revisions of this board run cooler or something? I bought it the day it came out so I have the first revision..

**EMC2** · 04-03-2005, 01:12 PM

If you can, position your fan so it blows *across* the board, not from above it. It'll run much cooler in the Vmem regulator area that way

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