It really depends if you have a really low power CPU because that card draws a lot of power at full load almost 190W. But then you have a dedicated 200W gfx cable so you maybe ok. It's a mild risk but the main concern would be airflow because the card gets hot unless you use RivaTuner or ATITool to set the fans speed to actually cool it down.
i got 76.48Watt result
Case temp 46C
CPU temp 51C
Should be sufficient with 2 12V rails of 17A each? I be getting the card this week. Support says it supports even Geforce 7800GTX in Shuttle's page. AT the moment i cant afford buying a new computer.
And the fact you said it's supports the 7800GTX i would say it'll be ok as the 3870 is more power efficient. Sounds like your onto a winner . Good luck with the card, that shuttles going to have a massive wake-up call .
YEP its last upgrade before i buy a new computer this year. I had my eyes on an AMD this year. The card arrives Monday or Tuesday from Manila. it cost Php 10,500.00 or roughly $257.00 with shipping already. Now All i have to do is save for a computer. I was thinking buying it from new egg. But its actually cheaper now here in our country. It's a miracle. I used to buy parts from U.S. because its cheaper.
its mentioned in Shuttle.
PCI-E nVidia Leadtek PX7800 GTX TDH 256MB
.If want use the nVidia 7800 VGA card,please remove the original fan duct. That will be no problem on thermal performance. 2.The nVidia 7800 VGA card requires a 6-pin power connectors,For the SB81P,will require to use power converter (supply with 7800) which takes up two 4-pin power connector.