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Message boards : Graphics cards (GPUs) : 128 or 256 bit memory width?

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Message 33451 - Posted: 11 Oct 2013 | 1:41:12 UTC

Hello guys,

I have two very, very slow gtx 460 gpu's. I have crunched before, two years ago more or less, but the cards were faster back then. They always met the 24h deadline on the long runs. I have looked around at other computers with this type of gpu and they are much faster. One thing that seemed odd was the memory width specification in the task info or log, I don't know how it is called. Here are a few examples:

http://www.gpugrid.net/result.php?resultid=7345678
http://www.gpugrid.net/result.php?resultid=7338412

These are just two examples but all the tasks have the same memory width specification, 128bit. However, the nvidia site states that this type of gpu has a 256 bit memory width.

http://www.geforce.co.uk/hardware/desktop-gpus/geforce-gtx-460/specifications

Now I don't remember if two years ago the memory specs were 128 bit or 256 bit but the card was much faster and without overclocking. I don't know if this is the reason why the cards are so slow but are they definitely slower than other gtx 460.

Here are some examples from another user:

http://www.gpugrid.net/result.php?resultid=7329950 and this is a 768mb
http://www.gpugrid.net/result.php?resultid=7335713
http://www.gpugrid.net/result.php?resultid=7345605

Can any of you help me understand what is going on? I would very much appreciate it.

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Message 33455 - Posted: 11 Oct 2013 | 9:46:22 UTC - in response to Message 33451.
Last modified: 11 Oct 2013 | 9:49:13 UTC

The tasks take longer because they are bigger.
Over the last 2years 8-12h on a GTX480 went to 8-12h on a GTX 680/770, and now there are even Titans and GTX780's. So if your GTX470 took 14h on a WU that took 8h on a GTX480 expect it to take around twice that to complete a WU that takes a GTX770 8h.

There are several types of GTX460; the originals, v2, OEM, SE.
The original came in two flavors, one had a 192bit bus and the other was 256bits.
The v2 model uses 192bits but the OEM and SE are 256bits.
There isn’t a 128bit version that I’m aware of. You would need to be dropping down to a GTS450 to be reduced to that width.

As for why your system is reporting 128bits. The links to your cards suggest a 256bit width card, but it's not being reported as such. Maybe an app bug, but are the cards setup in Sli? I think you are using a Beta driver (maybe issues there). Perhaps the cards are dropping down to 128bits because that think they don't need to operate any higher (an energy saving feature). You could check by going to NVidia Control Panel and selecting Prefer Maximum Performance. The only other thing that comes to mind is that some sort of peculiar hardware restriction is kicking in (motherboards/Bios, system memory limitation due to mismatched modules).
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Message 33456 - Posted: 11 Oct 2013 | 10:17:36 UTC - in response to Message 33451.
Last modified: 11 Oct 2013 | 10:22:24 UTC

Hello guys,

I have two very, very slow gtx 460 gpu's. I have crunched before, two years ago more or less, but the cards were faster back then. They always met the 24h deadline on the long runs. I have looked around at other computers with this type of gpu and they are much faster. One thing that seemed odd was the memory width specification in the task info or log, I don't know how it is called. Here are a few examples:

http://www.gpugrid.net/result.php?resultid=7345678
http://www.gpugrid.net/result.php?resultid=7338412

These are just two examples but all the tasks have the same memory width specification, 128bit. However, the nvidia site states that this type of gpu has a 256 bit memory width.

http://www.geforce.co.uk/hardware/desktop-gpus/geforce-gtx-460/specifications

Now I don't remember if two years ago the memory specs were 128 bit or 256 bit but the card was much faster and without overclocking. I don't know if this is the reason why the cards are so slow but are they definitely slower than other gtx 460.

Here are some examples from another user:

http://www.gpugrid.net/result.php?resultid=7329950 and this is a 768mb
http://www.gpugrid.net/result.php?resultid=7335713
http://www.gpugrid.net/result.php?resultid=7345605

Can any of you help me understand what is going on? I would very much appreciate it.


See my GTX460 and it still finishes most WU's within 24hrs with an OC from stock 675 to 750 giving a device clock of 1500
http://www.gpugrid.net/results.php?hostid=159137

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Message 33462 - Posted: 11 Oct 2013 | 14:26:05 UTC

Thank you for your input. It prompted me to contact with the manufacturer, Point of View. They actually confirm that they sold at the time I bought the computer a model with a 128bit memory interface. It was the VGA-460-A5-1024. I guess the vendors forgot to mention that when they sold me the rig. This should explain the difference in performance between my cards and Betting Slip's. I also found some settings in the NVidia Control Panel that weren't "performance friendly". Thanks skgiven. Now the settings are on Maximum Performance. Hope this helps a bit. SLI was disabled already.

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Message boards : Graphics cards (GPUs) : 128 or 256 bit memory width?