Graphics card for UP1500, AGP Compatibility and Signalling Voltages

[Alex Deucher]

On Thu, Nov 27, 2008 at 1:40 AM, Matt Turner <mattst88 at gmail.com> wrote:
> On Thu, Nov 27, 2008 at 1:26 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
>> On Thu, Nov 27, 2008 at 12:22 AM, Matt Turner <mattst88 at gmail.com> wrote:
>>> Hi,
>>>
>>> I'm attempting to determine what graphics cards are compatible with
>>> the Samsung UP1500 motherboard.
>>>
>>> It uses the AMD-761 chipset, which according to both the UP1500 user
>>> manual and this Wikipedia article
>>> (http://en.wikipedia.org/wiki/Comparison_of_AMD_chipsets) supports AGP
>>> 4x.
>>>
>>> AGP 4x is defined as using 1.5v signalling voltages, whereas older
>>> 1x/2x AGP used 3.3v. To prevent you from frying your card, AGP slots
>>> are keyed. See http://en.wikipedia.org/wiki/AGP#Compatibility
>>>
>>> Now, if you look at the picture of a UP1500 motherboard
>>> (http://alphalinux.org/wiki/index.php/Image:UP1500.jpg), it clearly
>>> has the 3.3v key. This limits the available cards to Radeons through
>>> the R300 series. I'd really like an AtomBIOS-enabled R500 to be able
>>> to go straight from the blue backgrounded SRM console to a nice kernel
>>> modesetting environment, but without the correct AGP keys, this can't
>>> happen.
>>>
>>
>> Your best bet is probably a PCI r3xx or r5xx card.  AGP is broken by
>> design and it's best to avoid it.  Also, drm kernel modesetting
>> support both legacy and atombios based cards, so either will work.
>
> Excellent! I'll have my SRM->KMS after all. :)
>
> Do R300 cards support any kinds of power management? If so, is it
> possible that support will be provided in the drivers?
>

DPMS :)

In theory the clock gating stuff could work on desktop cards but we
only ever supported it on mobile parts back then (r3xx-r5xx cards).
Changing the core and mem clocks should be possible eventually.

Alex