Low 12v reading on new OCZ Modstream Power Supply

[Glpster]

Well, I have set up my new system with the following components.

Chaintech VNF4
AMD Athlon64 3000+
1 GB (2x512) PQI PC3200 Turbo Memory
Maxtor DiamondMax SATA 250GB 16MB 7200 rpm
Leadtek WinFast 6600GT
BenQ 1620 DVD
Floppy

And the OCZ Modstream 450 Watt Power Supply

According to Sandra the voltage on my +12v rail is 11.42 volts! (I haven't installed much else, this being one of the very first programs installed, so this is a completely unstressed system so far).

Motherboard Monitor reads it as 11.52 volts, and the Bios says 11.5 volts!

Is this okay?? Running MBM5 overnight showed the lowest reading of 11.52v (which was the average also, and the high being 11.80 volts).

On my old PC with an Antech 350 watt supply, MBM5 had the +12 volt rail at a fairly stead 11.80 volts.

So, is this power supply F-ed up or is this nothing to be concerned about?

Thanks.

 

[imported_Computer MAn]

The readings might be off by a little bit so I would try it and see if it runs ok under load

 

[fstime]

RMA........

 

[tiap]

You are barley wihtin specs depending on the method of measure.
Here is a link to the acceptable specs
Specs

 

[Glpster]

Originally posted by: Computer MAn
The readings might be off by a little bit so I would try it and see if it runs ok under load

I am fairly new to this, so how would you (anyone?) recommend that I put my new system "under load" and test the voltage on the +12v rail?

Presumably I should run MBM5 for a period of time while running something that stresses the system? What is a good way to do this?

Thanks for your input.

 

[fstime]

Dude your readings are terrible, rma it trust me, I get 11.92V with a thermaltake 420 with a 3500+, and 6800nu, with 3 hardrives.

 

[BonzaiDuck]

Stress testing:

Hopefully, even under this low voltage reading, you can get a stable boot into the OS, and you have internet access. download PRIME95 and install it. I cannot at the moment remember the URL -- "mersenne.org" is probably the locatiion to find it.

Make sure your system is NOT over-clocked -- that it has all the stock settings. Run the "Torture Tests" -- "small FFT" and "Blend" for several hours each.

Low voltage readings:

I have replaced power supplies for this, even if they show 11.88V on the 12V rail but it drops to 11.5V under an over-clock setting. Personally, I would have purchased the "adjustable" OCZ PowerStream -- not the ModStream. That WAS a short-coming of OCZ in some reviews -- PSUs as shipped were not accurately adjusted. My PowerStream arrived "over the 12V spec" with a setting closer to 12.2 or 12.3V. But the PowerStream is adjustable, so I never felt that the careless voltage-rail settings were a drawback. I just "adjusted" them to near-perfect accuracy.

 

[Glpster]

Well, my system boots up and seems normal.

Is there any risk in running my system with a low 12v rail?

What would happen if it gets too low? Can anything be damaged?

Now the Bios is reading 11.71 volts, but MBM5 is still 11.52, and Sandra says 11.42v. Hmmm....

Also, is it possible it could be the motherboard? I disconnected most everything, and checked the Bios, it was reading 11.71 with everything connected and nothing connected.

 

[loafbred]

NEVER judge your p/s output by motherboard readings. You have to test p/s supply leads with a multimeter. Motherboards seldom give accurate readings. Here's a link explaining how to do it:

how to test p/s

Just use a 4 pin molex for 12v and 5v, and use an orange and black wire on that funky flat connector for 3.3v.

 

[Patrick Wolf]

I get 12.08 on my Modstream 450.

 

[Glpster]

Originally posted by: wolfman579
I get 12.08 on my Modstream 450.

Is that reading with Bios, a monitoring program (which?), or with a multimeter?

 

[Glpster]

Originally posted by: BonzaiDuck
Stress testing:

Hopefully, even under this low voltage reading, you can get a stable boot into the OS, and you have internet access. download PRIME95 and install it. I cannot at the moment remember the URL -- "mersenne.org" is probably the locatiion to find it.

Make sure your system is NOT over-clocked -- that it has all the stock settings. Run the "Torture Tests" -- "small FFT" and "Blend" for several hours each.

Low voltage readings:

I have replaced power supplies for this, even if they show 11.88V on the 12V rail but it drops to 11.5V under an over-clock setting. Personally, I would have purchased the "adjustable" OCZ PowerStream -- not the ModStream. That WAS a short-coming of OCZ in some reviews -- PSUs as shipped were not accurately adjusted. My PowerStream arrived "over the 12V spec" with a setting closer to 12.2 or 12.3V. But the PowerStream is adjustable, so I never felt that the careless voltage-rail settings were a drawback. I just "adjusted" them to near-perfect accuracy.

Is Prime95 more intensive than say SETI@Home ?

 

[Bozo Galora]

just run the sisoft burn in wizard

 

[thegimp03]

11.7+ is good as long as its stable. My ocz powerstream 420 sits at 11.734 all day and never budges...guaging this from asus probe.

 

[slpaulson]

The only way to be sure is to take a digital multimeter to it. Those bios readings can be way off.

 

[Amaroque]

Originally posted by: cRazYdood
The only way to be sure is to take a digital multimeter to it. Those bios readings can be way off.

Agreed.

Any BIOS reading, or HW monitor is just for a baseline reference only. Basically to see if there is any fluctuations. If it's running fine, I wouldn't be concerned at all.

You really have no idea what your true voltage is, unless you are using a multimeter.

 

[Glpster]

Alright, I guess I will test this with a multimeter as per Loafbred's link, and everyone's recommendation.

What will be an acceptable range for the +12v rail with a multimeter test?

 

[Mercmaster]

Yes, definitely test with a multimeter for accurate reading.

My powerstream runs 3.38, 5.10, and 12.34 tested with a meter but MBM shows 3.25, 5.03, and 12.25.

If you have any other questions, you may want to check out the OCZ support forum, a wealth of info can be found there as well as RMA support if needed.


MM

 

[sic wil]

Hi, I have an OCA Modstream 420w, and MBM gives me a reading of 9.7??? Is that a definite RMA or would a multimeter show that much difference???

 

[JimPhelpsMI]

HI, Tolerances for 5v and 3.3 volts is usually 5%. All others are usually 10%. Thats +/- 1.2 volts for the 12. Don't rely much on software devices to measure the voltages. Use a Digital Voltmeter. Ignore the first "flash" on most digital meters. The next one is accurate. Jim

 

[Glpster]

Okay folks, here are my Multimeter testing results for my OCZ Modstream 450. Please let me know what you think of these readings.

I tested these by inserting the multimeter probes into a spare molex connector.

The FULL range of values I observed on the +12 rail were as low as 11.67 volts, and as high as 11.80 volts. (11.67 - 11.80). I did not see any higher or lower voltages during any tests.

The detailed readings are:

+12 rail Voltage.....Tests
-------------------------------------------------------
<
r>11.79 to 11.80.......Sandra File System (Drive C) Test, Memory Bandwidth Test
11.78 to 11.79.......IDLE, Sandra USB Flash Drive & CD/DVD Tests
11.75 to 11.80.......Sandra Cache & Memory Benchmark
11.75 to 11.76.......3DMark05 CPU Tests
11.74 to 11.75.......3DMark03 CPU Tests, Sandra CPU Arithmatic & Multimedia Tests
11.74 to 11.74.......Prime95 Torture Tests (rock steady voltage)
11.71 to 11.73.......3DMark2001/2003 Demo
11.68 to 11.71.......3DMark2001/2003/2005 Benchmark Tests (most)
11.68 to 11.74.......3DMark05 Demo (Widest range observed)
11.68 to 11.68.......Final End Scene 3DMark05 (rock steady voltage)
11.67 to 11.68.......3DMark01 Nature Scene, 3DMark03 Battle of Proxycon, & some latter tests
--------------------------------------------------------

So what do you think? How are my voltages? Are they high enough? Steady enough? Do I have anything to be concerned about with this power supply?

Are there any other tests I could run to stress the power supply even more?

Oh, I didn't test the +5v rail as thoroughly, but the tests I did do (like USB Flash drive test, and 3DMark03 Bench & Demo), saw the +5v rail vary from 5.00 volts to 5.02 volts. (Very steady)

Thanks for your input.

 

[CraigRT]

every power supply I put into my system, my +12V rail reads 11.6-11.7, which annoys me, but it works fine, so I just disregard the dumb readout.

 

[BentValve]

Originally posted by: Glpster
+12 rail Voltage.....Tests
-------------------------------------------------------
<
r><
r>11.79 to 11.80.......Sandra File System (Drive C) Test, Memory Bandwidth Test
11.78 to 11.79.......IDLE, Sandra USB Flash Drive & CD/DVD Tests
11.75 to 11.80.......Sandra Cache & Memory Benchmark
11.75 to 11.76.......3DMark05 CPU Tests
11.74 to 11.75.......3DMark03 CPU Tests, Sandra CPU Arithmatic & Multimedia Tests
11.74 to 11.74.......Prime95 Torture Tests (rock steady voltage)
11.71 to 11.73.......3DMark2001/2003 Demo
11.68 to 11.71.......3DMark2001/2003/2005 Benchmark Tests (most)
11.68 to 11.74.......3DMark05 Demo (Widest range observed)
11.68 to 11.68.......Final End Scene 3DMark05 (rock steady voltage)
11.67 to 11.68.......3DMark01 Nature Scene, 3DMark03 Battle of Proxycon, & some latter tests
--------------------------------------------------------

So what do you think? How are my voltages? Are they high enough? Steady enough? Do I have anything to be concerned about with this power supply?

11.67 - 11.80 using what brand of Mutimeter?

Even the best mutimeters aren't fast enough to capture milisecond changes in power , my Fluke meter has a min-max feature where it can take a quick snapshot and get even more accurate readings.

For example in a warm room of around 70F ( I keep a digital thermometer near my PC for reference) , my FSP550 reads 12.12V , under load it drops to 12.11V ..if room temps are @ 60F then I get no drop whatsoever.

Now using min-max tells a different story...in a warm room under load the PSU drops to 12.08V and goes as high as 12.13V. In a cold room under load min-max reads 12.12 min and max.

So @ 65F or less my PSU has zero fluctutation at all.... @ 75F it has less than 1%.


Your MM may be inaccurate so I would not make any conclusions until you have used a true RMS meter on it...Sears sells some decent meters for around the $60 range.

Now if I personally measured 11.67 - 11.80 under any conditions on my PSU id be selling it asap. ...not that it is not acceptable but why settle for it when I can have a better PSU?

 

[Amaroque]

Are you having any stability problems? On average, it's about 3% low on the 12v rail (well within spec).

Looks good to me, nice steady voltages too. About a .12v fluctuation between min, max reading. That comes out to a 1% fluctuation.

Personally, I'd be happy with those readings.

 

[Glpster]

Originally posted by: BentValve

11.67 - 11.80 using what brand of Mutimeter?

Even the best mutimeters aren't fast enough to capture milisecond changes in power , my Fluke meter has a min-max feature where it can take a quick snapshot and get even more accurate readings.

For example in a warm room of around 70F ( I keep a digital thermometer near my PC for reference) , my FSP550 reads 12.12V , under load it drops to 12.11V ..if room temps are @ 60F then I get no drop whatsoever.

Now using min-max tells a different story...in a warm room under load the PSU drops to 12.08V and goes as high as 12.13V. In a cold room under load min-max reads 12.12 min and max.

So @ 65F or less my PSU has zero fluctutation at all.... @ 75F it has less than 1%.


Your MM may be inaccurate so I would not make any conclusions until you have used a true RMS meter on it...Sears sells some decent meters for around the $60 range.

Now if I personally measured 11.67 - 11.80 under any conditions on my PSU id be selling it asap. ...not that it is not acceptable but why settle for it when I can have a better PSU?

I am using a very simple, very basic, very cheap, Cen-Tech P30756 Digital Multimeter. It claims to have a DC Volatage accuracy (for at least 1 year) between 18 - 28 C, of +/- 0.5% of rdg +/- 2D. (The room is 21 C, and the MM is brand new.)

As mentioned the fluctuation on this PSU on the 12v rail is less than 1%. You are saying this PSU is bad, yet others are saying that it's fine.

I bought the PSU because it was an OCZ and reputedly one of the best brands of PSU one can get.

So, I think I'm going to need some additional input. So far I see one vote for *Your PSU is crap. And one vote for *Your PSU is perfectly fine.

Oye! Anyone else?

Thanks.