Finding 1070, 1080 mxm cards

This kind of upgrade can be tricky. As you mentioned, the 1070 uses more power so you would very likely need to upgrade your power brick. From what I understand, the Deskmini GTX uses the standard MXM connector and form factor so in theory, any MXM GPU that meets the supported MXM standards should work. There is a 1080 model Deskmini and it does indeed ship with a higher output power brick, 270w vs the 1060 model's 220w.

However, this is where things get tricky. MXM is not as standardized as regular PCIe and some vendors will use proprietary firmware versions that may not be compatible with other systems. In other words, you will want to look for universal MXM GPUs that are not brand specific (acer, dell, HP, Lenovo etc) to be safe. I suspect ASRock made the Deskmini BIOS as compatible as they could with different vBIOS versions but there is always a chance that a branded MXM GPU has a proprietary vBIOS to ensure it only works on systems it's designed to.

If you do go down the route of upgrading your MXM GPU, please post back with your results, I would love to know how it goes for you. Don't forget to upgrade the power brick.

Furthermore, it seems that there are cheaper alternatives by going to a vendor laptop upgrade page and getting a MXM kit from there which is somewhat cheaper (http://www.eurocom.com/ec/upgrade(3,427,0)MS_GT73VR). 864 for P&P+tax is not cheap but it surely beats the previous post. I am a bit skeptical on compatibility but its a type B therefore is should have any issues. They include X-bracket, screws, thermal pads, ICD7 in the final price.

Apologies in advance in case it has been asked before. I am thinking of purchasing an Asrock deskmini 1060 gtx b250m. Although the 1060 is exceptional where could I find an asrock approved 1070 or 1080. Ebay has some options available but I am reluctant to order. Does Asrock have any dealers to order mxm cards? Thank you.