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b3ta
08-02-05, 06:58 AM
Just got this system:

Win XP Pro/SP2
Asus A8N-SLI Deluxe
Athlon XP 3700+
2 x OCZ PC3200 1 Gig DDR
1 x 36 Gig WD Raptor (page file)
2 x WD Raptor 74 Gig RAID 0 (system)
2 x Seagate 400 Gig RAID 0 (mass storage)
2 x GeForce 7800 GTX
Creative Audigy 2 ZS Platinum Pro
X Connect 500 PSU (34 Amp 12v rail)

from Overdrive PC. Running the 80.40 beta drivers. I noticed that both 7800's are powered through a single power line (jumped one to the other). Nothing else on the power line.. it IS dedicated to the cards (and the Asus PCIe Easy connector also has power). I'm just wondering if these cards need a separate power line for EACH.

The machine is absolutely a primo build and these guys OCed the heck out of everything... they really know their business and it's a screamer. 12,835 3Dmarks, 106 Mbs/sec. sustained transfer on the RAIDs, CPU clocked at 2.75 Ghz, RAM tweaked, etc. I only draw about 385 watts on the PSU when pushing the system so I don't think the PSU is underpowered, but I'm concerned that both cards are running off of one power line.

Any thoughts from all you great folks that are far more knowledgeable than I?

b3ta

Zurble
08-02-05, 07:10 AM
each card need a 6pin 12V plug . on my OCZ 520, there is only one 6pin cable coming out of my PSU so i have to use Two other standard plug for the 6Pin adapter of the second card (the adapter need 2 standard 12V connector)
if i had another OCZ 6 pin cable, it would reduce to 2 'line'.
i never saw a double 6Pin cable using only 1 cable, but it seems that this is what you get.

I don't think it is an issue, the 12V lines are serialized in the PSU, the most important is to have enought Amps on THE 12V line which you have by far (i say THE because i think there is 1 line anyway on most of the PSU)

now if you have thoose rare PSU with 2 separate 12V line (dual rail), you can make use of it, but it won't help much if you don't have many 12V devices (it help stabilize your voltage)

now i talk about something i recall, so i can be totaly wrong, but by judging your scores....you don't need to worry

b3ta
08-02-05, 07:57 AM
Thanks a lot for the info. I had a feeling that it wouldn't matter how many separate lines came from the 12v rail but wasn't sure.

The guys at Overdrive actually adapted a cable (you can see where they cut the pgitail and spliced on an additional 6 pin).

I was just concerned that maybe the first card on the line would be pulling too much and "robbing" the second one when I was really pushing the cards. I play EQ II and was able to run at Extreme Quality outside of town but when I went into town I started getting flashing and/or missing textures and my first thought was the cards were starved for power when the demand went up.

I'm going to monitor heat this evening and see what I can see. Overdrive has a nice series of fans to allow for OCing on air that seems to work really well, but I haven't actually gotten the monitored figures yet.

Do you have an idea for a good utility to give me a readout on seperate heat info and power draw info for both cards? Rivatuner maybe?

b3ta

aZn_plyR
08-02-05, 03:00 PM
holy crap someone powering 2 7800gtx in an ultra x-connect 500watt psu!!! ur a brave man..brave...

Ninjaman09
08-02-05, 03:06 PM
holy crap someone powering 2 7800gtx in an ultra x-connect 500watt psu!!! ur a brave man..brave...
Why do you say that? It's a great PSU, maybe the connectors are a little big, but if they fit it's pretty much top-notch.

@ b3ta: Your system is fine. Now quit worrying and play some games. ;)

SsP45
08-03-05, 12:37 AM
Why do you say that? It's a great PSU, maybe the connectors are a little big, but if they fit it's pretty much top-notch.

@ b3ta: Your system is fine. Now quit worrying and play some games. ;)

Compared to a good Antec, Enermax, or PC Power and Cooling the X-Connects are pretty bad power supplies. In my experience X-Connects are not very reliable at all, and usually don't have provide stable power.

tristancarton
08-03-05, 01:36 AM
no. (just another backup for az and ssp) go to any overclocking board whether it be xtremesystems, ocforums, bleedingedge, or extremeoverclocking and they will tell you the xconnect power supplies are not the best power supplies you can buy and most people there would be very very very hesitent to run a loaded sli system off of one of them.

that being said if the computer is stable and you are happy b3 then more power to you. a few hours of gameplay in a game like hl2 or bf2 should give you an idea if keeping the sli cards on one connector is going to be an issue.
Why do you say that? It's a great PSU, maybe the connectors are a little big, but if they fit it's pretty much top-notch.

Zurble
08-03-05, 04:02 AM
i don't know that PSU, but 34 Amps on 12V rail for a 500W PSU is prety high.
it's not like all thoose brands marketing 500/600W (almost always peak W) and barely having more then 20 amps

my 520 OCZ is 'only' 28 Amps and i still have rooms in my overclocked CPU/GPU SLI system

for stability, indeed you would probably prefer active PFC PSU with high quality components and so on...don't know much about x-connect on this

b3ta
08-05-05, 08:49 AM
Compared to a good Antec, Enermax, or PC Power and Cooling the X-Connects are pretty bad power supplies. In my experience X-Connects are not very reliable at all, and usually don't have provide stable power.


Interestingly enough I was concerned about that, too (having read some of the comments out there). When talking to Mario at OPC prior to purchase, I had originally asked for the PC Power and Cooling 520 they sell and he told me that they had sent out many, many SLI rigs using the Xconnect and never had a problem so I should save some money and go with it. If you go to slizone.com and read their suggested PSU capacities based on system load tables you'll see that they say only a 25 Amp 12v rail and 500 watt supply will run a FX55, 4 Gig of ram, 4 HDs, 2 optical drives and 2 6800's no sweat. And, the 7800's use LESS power than the 6800's.

I have been watching the voltages while pushing the cards and have to say that I've never seen anything below 11.7 and there's plenty of headroom left as far as total Amps goes. Heat isn't an issue either as I never seem to go above about 38C in the case (excellent cooling solution by OPC gets the nod for this).

I've run EQ II on Very High Quality (one step below max with character texture detail backed off to High because of the texture flicker bug in the 80.40 leaked driver) for extended periods now and have never had a problem with either heat or voltages. Even bumped it up to Extreme Quality outside town and could actually play a bit (probably about 12 - 15 fps solo, not grouped). Never the first problem... CPU gets to about 45C, GPU's to about 68C and case to about 40C is the max I've seen (according to Everest anyway), even after 4 hours + hard at it.

*shrug* Maybe I'm just lucky.... or maybe the guys at OPC really ARE that good... :D

Ninjaman09
08-05-05, 12:58 PM
Eh, I was just going by reviews, never actually used an X-Connect supply. All the reviewers seemed to think highly of it.

OWA
08-05-05, 01:23 PM
If it's running well for you, I wouldn't worry about it. Nice system btw.