There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

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There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

Note that this means I have nothing else to compare my readings to.

There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

Note that this means I have nothing else to compare my readings to.

So next time I have the skins off, I'll do the measurement on my 8000 and one of the Z400s. Also, could do the same on the Gigabyte box, if it helps ... Goodness knows I have the skins off stuff often enough.

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Note that this means I have nothing else to compare my readings to.

From Intel's ATX power specs ver. 2.1:

4.1.4  Voltage  Tolerances  
Tolerance for the motherboard power rails should comply with the values listed in Table 6. 
Table 6.  Voltage Tolerances 
Voltage Rail  Tolerance 
+5VDC           ± 5 % 
-5VDC (if used) ± 10 % 
+12VDC          ± 5 % 
-12VDC          ± 10 % 
+3.3VDC         ± 4 % 
+5VSB           ± 5 % 

Hope this helps ...

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There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

. . You have roused my curiosity, I may have to take the cover off my own rig to see :) Not that I am having any issues ... :)

Stephen

.

Note that this means I have nothing else to compare my readings to.

From Intel's ATX power specs ver. 2.1:

4.1.4  Voltage  Tolerances  
Tolerance for the motherboard power rails should comply with the values listed in Table 6. 
Table 6.  Voltage Tolerances 
Voltage Rail  Tolerance 
+5VDC           ± 5 % 
-5VDC (if used) ± 10 % 
+12VDC          ± 5 % 
-12VDC          ± 10 % 
+3.3VDC         ± 4 % 
+5VSB           ± 5 % 

Hope this helps ...

I think this is too wide a tolerance for graphic cards under full load to still produce valid results, especially the right-on-the-edge GTX 560. That was certainly the case when I ran a GTX 560. I would be looking closer to a 1.5% tolerance on the +12V rail. This being measured with a multimeter and not depending on a motherboard chipset sensor that can have very large errors depending on how it was setup in calibration by the motherboard vendor. Main thing to measure is the +12V rail NOT under load, that is not crunching, and then under full load of BOINC with whatever tasks per card you are using in your configuration. I would like to see the voltage sag under load.

---

Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Note that this means I have nothing else to compare my readings to.

From Intel's ATX power specs ver. 2.1:

4.1.4  Voltage  Tolerances  
Tolerance for the motherboard power rails should comply with the values listed in Table 6. 
Table 6.  Voltage Tolerances 
Voltage Rail  Tolerance 
+5VDC           ± 5 % 
-5VDC (if used) ± 10 % 
+12VDC          ± 5 % \
-12VDC          ± 10 % 
+3.3VDC         ± 4 % 
+5VSB           ± 5 % 

Hope this helps ...

. . Helpful info to have but he won't be testing the 3.3V rail from a molex connector :), nor the negative 5V/12V rails either for that matter. But still good to have for a reference.

Stephen

. . PS Never try and test a switch mode PSU's voltages without a load, they don't like it and tend to go ... POOF! Just in case you didn't know.

[Edit] to clarify that in view of Keith's remark I am talking about no load at all as in not connected to the motherboard or equivalent device, while Keith's comment refers to a nominal load such as a motherboard et al at idle which is safe to do.

.

[pre]
4.1.4 Voltage Tolerances
Tolerance for the motherboard power rails should comply with the values listed in Table 6.
Table 6. Voltage Tolerances
Voltage Rail Tolerance
+5VDC ± 5 %
+12VDC ± 5 %
Hope this helps ...

I've had issues when the error was less than 2%, however in those cases it was due to faulty caps; so lots of noise on the rails & the DC voltage still being pretty close to what it should have been.
Lower voltages than specified will generally give more issues than higher voltages for a given deviance from the specified value.
eg
12.0V nominal
11.8v is more likely to give problems than 12.2V.


EDIT- would be a good idea to monitor the voltages while booting up. Ideally there should be no change from when the system is first turned on to when the desktop is up & BOINC is crunching.

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Grant
Darwin NT

I've had issues when the error was less than 2%, however in those cases it was due to faulty caps; so lots of noise on the rails & the DC voltage still being pretty close to what it should have been.
Lower voltages than specified will generally give more issues than higher voltages for a given deviance from the specified value.

. . I think you mean deviation, deviance is me on a Saturday night :)

Stephen

.

Note that this means I have nothing else to compare my readings to.

From Intel's ATX power specs ver. 2.1:

4.1.4  Voltage  Tolerances  
Tolerance for the motherboard power rails should comply with the values listed in Table 6. 
Table 6.  Voltage Tolerances 
Voltage Rail  Tolerance 
+5VDC           ± 5 % 
-5VDC (if used) ± 10 % 
+12VDC          ± 5 % \
-12VDC          ± 10 % 
+3.3VDC         ± 4 % 
+5VSB           ± 5 % 

Hope this helps ...

. . Helpful info to have but he won't be testing the 3.3V rail from a molex connector :), nor the negative 5V/12V rails either for that matter. But still good to have for a reference.

Stephen

. . PS Never try and test a switch mode PSU's voltages without a load, they don't like it and tend to go ... POOF! Just in case you didn't know.

Good, accurate information. The 3.3V rail is mainly used on the CPU but unfortunately DOES make an appearance on the PCIe slot connector. The -12V rail can mostly be ignored in modern hardware, it only had a use in the RS-232C serial port which has mostly disappeared from current motherboards.

---

Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I finally caught a task postponed by a suspicious spike.

[url]http://setiathome.berkeley.edu/result.php?resultid=5166941169
[/url]
Appears to have some kind of restart. Mentioned a spike in the output, without mentioning suspicious.

I finally caught a task postponed by a suspicious spike.

http://setiathome.berkeley.edu/result.php?resultid=5166941169

Appears to have some kind of restart. Mentioned a spike in the output, without mentioning suspicious.

Corrected to make link clickable

. . Helpful info to have but he won't be testing the 3.3V rail from a molex connector :), nor the negative 5V/12V rails either for that matter. But still good to have for a reference.

Stephen

. . PS Never try and test a switch mode PSU's voltages without a load, they don't like it and tend to go ... POOF! Just in case you didn't know.

Good, accurate information. The 3.3V rail is mainly used on the CPU but unfortunately DOES make an appearance on the PCIe slot connector. The -12V rail can mostly be ignored in modern hardware, it only had a use in the RS-232C serial port which has mostly disappeared from current motherboards.

. . Some hardware used +/- 5V to drive their RS232 but the good stuff used the +/- 12V as per the RS232 specs. As you point out, USB has rendered RS232 obsolete unless you really need to interface with older equipment that lacks USB ports. Though even then most would use a USB to RS232 adaptor. Can you think of what else uses the -5V? In any case even the 3.3V on the PCIe slot does not have a major function that I am aware of. Mainly it is the +5V and the +12V that do the heavy lifting. The -5V and -12V only ever had low current ratings as I remember. But for the +5V and +12V better to be a little high than a little low as Grant pointed out.

Stephen

There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

If you really want to see something scary you should use an oscilloscope to view your power rails at idle & with BOINC running apps.
I did that a few years ago on one of my machines.

---

SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

. . Some hardware used +/- 5V to drive their RS232 but the good stuff used the +/- 12V as per the RS232 specs. As you point out, USB has rendered RS232 obsolete unless you really need to interface with older equipment that lacks USB ports. Though even then most would use a USB to RS232 adaptor. Can you think of what else uses the -5V? In any case even the 3.3V on the PCIe slot does not have a major function that I am aware of. Mainly it is the +5V and the +12V that do the heavy lifting. The -5V and -12V only ever had low current ratings as I remember. But for the +5V and +12V better to be a little high than a little low as Grant pointed out.

Stephen

And of course, RS-232 to USB adapters have been the bane of my hobby since I still have to use legacy hardware with serial ports. I typically have 3 in use to drive my scopes, mount and camera interfaces every night. Only in the last couple of years or so have the manufacturers started transitioning to USB or Ethernet interfaces. I believe the -5V and -12V were only used for balanced transmission systems like RS-232 or RS-432 or sometimes in early DC-DC inverters or analog op-amp audio circuits. The ATX12V 1.3 standard dropped the negative rails entirely.

---

Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

If you really want to see something scary you should use an oscilloscope to view your power rails at idle & with BOINC running apps.
I did that a few years ago on one of my machines.

. . I suspect I don't really want to see that :)

Stephen

.

There's a suitable power plug or two. I just ordered a multimeter.

Will be very interesting to see how the 5/12v moves when BOINC is and is not running... can't say I've tested that, either ...

If you really want to see something scary you should use an oscilloscope to view your power rails at idle & with BOINC running apps.
I did that a few years ago on one of my machines.

. . I suspect I don't really want to see that :)

Stephen

.

Have done it out of curiosity since my now aged Corsair 1200AX PSU came with ferrite chokes on the PCIe power cables. turned out the GTX480 I was running at the time was quite capable of polluting the 12V on the single rail PSU, and the chokes did the trick. Can easily see multi-GPU rigs suffering stability problems without some or another approach to mitigating the noise. While I believe newer GPUs would tend to use higher frequency converters and use less current than a GTX 480, it was a bit of an eyeopener as to the possibilities for subtle system instability, and the importance of quality power.

---

"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

Until the voltmeter arrives, I won't be able to continue the planned tests.

So, I've decided to try my other graphics boards in place of the 560 to see if they are also affected by whatever the problem is.

Until the voltmeter arrives, I won't be able to continue the planned tests.

So, I've decided to try my other graphics boards in place of the 560 to see if they are also affected by whatever the problem is.

. . A very good idea. That should prove the problem into either the GTX560 or the rig itself. Should have tried that earlier. You may have to reset your fan profile in Afterburner as it will react to the change of GPU.

Stephen

.

GTX 560 alternates:

I first tried the GTS 450, previously used in the same computer. The software initially thought it was a 9800 GT (the original graphics board for this computer), and BOINC didn't even recognize it as usable.

I then tried reinstalling the 362.00 driver; the driver installation program didn't recognize the GTS 450 as compatible with that driver.

I then tried installing the oldest driver I already had downloaded, 340.52. It installed, but still considered the board a 9800 GT.

I'm out of ideas, so I asked Nvidia. Do you have any other ideas?