# Wanted to share: Dual PSU Action



## JrRacinFan (Jun 15, 2008)

While testing to find stable clocks with my motherboard I decided to connected a dedicated power supply for graphics. I found out the easy way that all my instabilities are not caused by power consumption. 







I know this is not a pretty site with wires but the power supply stays cool and does not even get remotely warm. Any comments/suggestions are welcome. 


Main question being to my post though is this, Leave it or remove it?


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## intel igent (Jun 15, 2008)

any improvement's at all?


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## JrRacinFan (Jun 15, 2008)

None really intel. All I have noticed is that i can push CL4 up to my max fsb.


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## Cold Storm (Jun 15, 2008)

Bro, I think its crazy that you have that you did it! But, it works! Just have to see if its "safe"!


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## JrRacinFan (Jun 15, 2008)

Perfectly safe man. I've been running with this all this morning. I will leave it in for a few days and see how well it does.


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## intel igent (Jun 15, 2008)

JrRacinFan said:


> None really intel. All I have noticed is that i can push CL4 up to my max fsb.



at max FSB without the added PSU what are you at CL5?

i dunno if all you get is 1 bump in CL timing and everything else is equal....

any improvement on the GFX side?

have you run any benches?


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## JrRacinFan (Jun 15, 2008)

Been running benches all morning. Only improvement is the jump to CL4.


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## intel igent (Jun 15, 2008)

no increase in FSb of GFX clock's?

have you tried to put only the MOBO on main PSU and GFX/peripheral's on the second?

what does the CL4 give you? anything noticeable?


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## JrRacinFan (Jun 15, 2008)

No increase in vid card clocks .. 

I can try the hdd's/optical if you want and post back.

CL4 drops about a second off my superpi


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## intel igent (Jun 15, 2008)

it's not for me your trying, it's for you 

i'm just making suggestion's


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## Cold Storm (Jun 15, 2008)

I think doing that would be a great idea. Puts less onto the computer.


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## JrRacinFan (Jun 15, 2008)

After doing what was suggested. This the good reason to push for a good psu.









And I have a little bit of room to go.


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## intel igent (Jun 15, 2008)

what were your #'s prior to this?

edit : you were at 2.5 before? not bad an extra 400mhz!


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## panchoman (Jun 15, 2008)

jr, if you're not getting anything outta the dual psus, you're better off sticking with 1 psu. i imagine you'll be on a worse part of the efficency curve and its just much more of a hassle really..


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## JrRacinFan (Jun 15, 2008)

Yup working on it pancho. Lookin at some new motherboards. Once I get that I will resurrect the dual psu project. I just noticed thats its more stable and mroe responsive.

@intel

Thats my max stable right there at CL4.


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## intel igent (Jun 15, 2008)

so you gained 400Mhz and bumped up to CL4?

if so


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## JrRacinFan (Jun 15, 2008)

Disconnecting the slave psu for now until I get a new motherboard. It gives me no true noticeable improvements due to the 975x chipset. If I had a P35/X38/P45, then this would be a different story. Not much more to see here.


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## Cold Storm (Jun 15, 2008)

Well, at lease it shows you what is needed. You've tried all there is to try before getting a new board.


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## Xazax (Jun 15, 2008)

Personally, i would get one of those "dedicated" PSU's for the Graphics card ive seen a few, that might help more having your dual PSU's 

But yea your crazy...


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## farlex85 (Jun 15, 2008)

Seems to me this would only be useful if you vmod the graphics card, or if you have water on the proc and thus are able to push large amounts of power through it. W/ an unmodded card and air cooling, there doesn't seem to be much reason for it imo.


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## JrRacinFan (Jun 15, 2008)

Thanks for the input farlex. Like I was saying, I just needed to test and make my instabilties werent due to an underpowering psu. Thank you all for your opinions.


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## farlex85 (Jun 15, 2008)

JrRacinFan said:


> Thanks for the input farlex. Like I was saying, I just needed to test and make my instabilties werent due to an underpowering psu. Thank you all for your opinions.



Ah yes ok I see. Yeah that does seem like a good way to test for that. I'll keep that in mind if I ever run into a similar situation.


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## Xazax (Jun 15, 2008)

BTW what are you watts and amps on those PSU's?


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## JrRacinFan (Jun 15, 2008)

The Antec 500W: dual 12v 18a. The @Power 550W: single nominal 24a/max 28A.

@farlex

Just figured since it wasn't an underpowering psu might have wanted to play around and bench a little. Didn't work out as well as I wanted.


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## dark2099 (Jun 15, 2008)

Possibly with a better board that will be helpful, I'll definitely keep a close eye and maybe fiddle with that some time.


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## JrRacinFan (Jun 16, 2008)

@dark

Yeah, it can be quite fun when doing benchmarking.

After doing some testing from yesterday spanning into today. Idid find I will need a new power supply if I want to overclock the HD3870. If I do not run it overclocked the whole system is fine on my single Antec.


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## Skitzo (Jun 16, 2008)

JrRacinFan said:


> Disconnecting the slave psu for now until I get a new motherboard. It gives me no true noticeable improvements due to the 975x chipset. If I had a P35/X38/P45, then this would be a different story. Not much more to see here.



So what kind of improvments would you expect with a P35?  I only ask because I have one and I like to mess with shit


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## dark2099 (Jun 16, 2008)

The 975x chipset is a bit aged, so my guess it is limiting his overclock on the processor, from talking with him and doing some research, the board can't reach as high of an FSB as the newer chips so to a point his motherboard and CPU combo are being coming a bottle neck for his 3870.


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## Skitzo (Jun 16, 2008)

ok thanks.  well I have fairly decent oc with one psu so I'm thinking there wont be much of a benifit till I v-mod the 9600.  My biggest problem at this point is cpu cooling, after I deal with that then maybe this would help.  I wouldn't want a smaller psu for my setup, but this one seems to be doing the job for now.

EDIT:  however this might let me push the 9600 higher at factory voltages


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## JrRacinFan (Jun 16, 2008)

I have noticed, if you reference to the SuperPI 1M thread. I can push CL4 timings acrossed my ram. Oh and dark, 381 fsb is my absolute max SuperPI benchable on this board.


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## ntdouglas (Jun 16, 2008)

Cool Jr. Now I don't feel like the only one. I have a 550w antec for the board and drives and a Thermatake 400w for my 2 9600 gt's.


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## MilkyWay (Jun 16, 2008)

energy efficiency down the crapper and the bills would increase

if you dont need 2 what is the point? you can just get a higher watt PSU


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## JrRacinFan (Jun 16, 2008)

@ntdouglas

I dunno, I am getting mixed results unsure if its my psu or my motherboard holding my clocks back. I know it definitely isn't both.

@KeiranD

But this way is cheaper if you already own a strong (but not strong enough to power all components) second psu. Also, a power supply will only draw what is needed up to its maximum.


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## ntdouglas (Jun 17, 2008)

What kind of mixed results are you talking about?


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## JrRacinFan (Jun 17, 2008)

I dunno it just seems like that its a more responsive overclock with the 2nd psu, getting the same clocks and ram timings with both options.


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## ntdouglas (Jun 17, 2008)

JrRacinFan said:


> I dunno it just seems like that its a more responsive overclock with the 2nd psu, getting the same clocks and ram timings with both options.



It was probably already mentioned in this thread, but what board are you running?


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## JrRacinFan (Jun 17, 2008)

ntdouglas said:


> It was probably already mentioned in this thread, but what board are you running?



See specs, aw9d-max. An old school 975x chipset.


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## ntdouglas (Jun 17, 2008)

If its working, why fix it? Just leave both psu's in it.Two has got to be better than one for video cards right?


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## JrRacinFan (Jun 17, 2008)

Hmmm, I guess you do have a point there. How should I mount the 2nd though? I don't have a dremel to mod the case.


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## kyle2020 (Jun 17, 2008)

it does, based on looking at your epenis benchmark results, seem like your motherboards doing some tasty bootlenecking. And of course if thats whats causing your instabilities along with the PSU issue, it looks like a new board is the only way to go.


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## intel igent (Jun 17, 2008)

MilkyWay said:


> energy efficiency down the crapper



wouldn't efficiency increase because your'e splitting the load?


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## JrRacinFan (Jun 17, 2008)

Also, a psu will only draw what it truly needs. Wait until I get this new board then we will see if it truly does help any. 

@kyle

Its not a psu issue at all.


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## kyle2020 (Jun 17, 2008)

JrRacinFan said:


> Also, a psu will only draw what it truly needs. Wait until I get this new board then we will see if it truly does help any.
> 
> @kyle
> 
> Its not a psu issue at all.



by issue i meant using 2


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## JrRacinFan (Jun 17, 2008)

I dont have to use both at all. Its motherboard crappy chipset problem. I don't understand and know where your going witht hat comment. Please elaborate more.


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## kyle2020 (Jun 17, 2008)

i was mainly talking about your benchmark results and commenting on the fact that a new motherboard seems the way to go, be it for the bottleneck or the instabilities your experiencing and that possibly a higher power PSU rather than using 2 would be better.

Sorry for my un-clear post haha, hashed it out quick and nipped out to the shop


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## JrRacinFan (Jun 17, 2008)

Ahhh, I understand. Obviously, once I get the new board I will try it out. I understand completely about the single vs. dual thing, same can be said for Xfire/SLi.


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## kyle2020 (Jun 17, 2008)

JrRacinFan said:


> Ahhh, I understand. Obviously, once I get the new board I will try it out. I understand completely about the single vs. dual thing, same can be said for Xfire/SLi.



thank god haha, thought you where going to come and punch me or something 

Got any new boards in mind like?


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## JrRacinFan (Jun 17, 2008)

Check out my Soon To Be in my specs! 

Asus P5K or DFI LP P35 Dark.


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## vexen (Jun 17, 2008)

intel igent said:


> wouldn't efficiency increase because your'e splitting the load?


one 85% eff. PSU *> two 80% eff. PSU


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## ntdouglas (Jun 17, 2008)

JrRacinFan said:


> Check out my Soon To Be in my specs!
> 
> Asus P5K or DFI LP P35 Dark.



Man Jr. Your getting 10.3 on 3dmark06 with a celeron? I thought that was a little more cpu intensive.


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## p_o_s_pc (Jun 17, 2008)

JrRacinFan said:


> Perfectly safe man. I've been running with this all this morning. I will leave it in for a few days and see how well it does.



I have done that before when i had my 7900GS and had the Sempron when i was trying for a 100% overclock on the CPU. I didn't have a problem with it. Something you could also do is if you have any LEDs or anything else that runs off 4pin then you could also use the PSU to run them.


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## cdawall (Jun 17, 2008)

you could get a drive bay PSU so its not as messy  like the one i have 

i saw a 130mhz increase on both VGAs and cpu still tops out the same


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## JrRacinFan (Jun 18, 2008)

cdawall said:


> you could get a drive bay PSU so its not as messy  like the one i have
> 
> i saw a 130mhz increase on both VGAs and cpu still tops out the same



Well, card is max benchable @ 877/1230, and I can attain that on the single psu. I can fix the messiness but I don't have a dremel to mod the case to make it fit and look nice. 

Just waitin' on a new motherboard .....


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## JrRacinFan (May 8, 2009)

Been a year guys, same 2 power supplies still kickin' strong. Granted, since this thread was made I had went with 2 different motherboards. DFI LP Dark & this MSI 750i. I do run the 2nd psu only when benching. So just a long well needed update.


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## silkstone (May 8, 2009)

I've got a spare PSU lying around so i could try this, but no room in my case  plus i have the video card running off 1 rail and the cpu of the other, i should have enough power there already. interesting thread tho. I was thinking of doing this if i ever went xfire


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## JrRacinFan (May 8, 2009)

If you need help just ask. All it is a matter of grouding the "PWR-ON" Green in I beleive pin 15 of the main ATX connector and using the rear switch to turn on the psu -OR- splicing pins 14 & 15 from slave to the corresponding primary pins 14 & 15 of each power supply respectively to turn both supplies on at the main power switch on your case.


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## silkstone (May 8, 2009)

Thanks Jr, not going to be doing it for a while. i need a new case + mobo + video card first.
I was wondering about how to get them both to turn on via the pc power switch tho.


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## Kweku (May 8, 2009)

Good idea, get a better board and see how far it goes, but sort out your cooling with some good water cooling and try push it to the gates of heaven... Don't forget to post some pics and scores, when you happy clean up the cables and post again with a lil case mod and you good to go.


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## JrRacinFan (May 8, 2009)

silkstone said:


> Thanks Jr, not going to be doing it for a while. i need a new case + mobo + video card first.
> I was wondering about how to get them both to turn on via the pc power switch tho.



Video card? IMO Video card is fine. As for board....

What's your 24.7 clock and what speeds on the ram?


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