VincentP :
The Nvidia reference GTX 750 Ti does not require a PCI-E power connector.
The MSI card N750Ti-2GD5/OC does not require a PCI-E power connector.
Some GTX 750 Ti cards from other manufacturers do require this connector though. These cards don't follow the reference design and may want to allow additional headroom for overclocking. An example is the Asus GTX750Ti-OC-2GD5.
The card draws 92 watts , say 115 at max overclock.
A PCI-E 3 slot I think is more than capable of handling that load....... For years I have only recommended cards with non reference boards and beefed up VRMs.... one of the reasons I would never recommend a EVGA SC as the SC series used reference PCBs and the others (Giga, Asos, MSI used custom).
But many vendors with the 7xx series, even on the 780 Ti, are moving away from that practice for several reasons:
1. Unless the card is very popular, water block manufacturers have been cutting down on making WB's for custom PCBs
2. Nvidia's steps in preventing voltage increases above stipulated limits has reduced the *need" or reasoning behind custom PCBs and bigger VRMs.
3. Given the above, the cost / benefit ratio is no longer present as it once was.
That's one of my biggest disappointments with reviewers of late....while with the 5xx series, reviewers oft detailed the different PCB designs, now it's rarely if ever mentioned. Looking at the MSI's PCB for the 750 Ti, as far as I can tell it's a reference PCB in which case the nVidia reference specs apply.
What is really odd is, Asus still is using the custom PCB as with the 650 Ti with the extra power connector, yet didn't think well enough of their design to up the core past 1072 MHz and yet ...... MSI with the reference design and no power conenctor, went to 1085 which tells ya that the the card should be able to run on PCI-E slots w/o the need for a 6 pin connector.
With the PCBs for 7xx being basically revamped 6xx designs, m guess is Asus has plenty of the leftover custom PCBs around.
As for the PCI-E spec, I find it totally confusing in that the w/ PCI-E 3 ya supposed to get (slide 11):
http://www.pcisig.com/developers/main/training_materials/get_document?doc_id=fa4ec3357012d69821baa0856011c665ac770768
25 watts from edge connector
50 watts from each 2 x 3 connector
100 watts from each 2 x 4 connector
So max shud be 225 now (25 + 100 + 100)
And yet the cables are rated at 75 watts and 150 watts .... and the difference between the 6 and the 8 is two extra ground wires.
But yet we have cards drawing more than 300 watts. My Asus 780s are 254 watts at stock and they have a 2x4, 2x3 and edge connector....I'm reading 175 watts max per the PCI spec (25 + 50 + 100) and 250 per the cable spec (25 + 75 + 150) yet yet I pull close to a measured 300 watts OC'd.
And the 92 watt 750 stock reference card has no connectors so if slot limited to just 25 watts, where's the power coming from ? And yet the Gigabyte Windforce, a factory overclocked card tested out at just 90 watts and it does have the power connector. And they both overclocked just about the same amount
Reference 750 Ti - No power conenctor
92 watts - Core Clock: 1155 / 1376 Boost / Memory Clock: 6696 MHz
Windforce 750 Ti - w/ power Conenctor
90 watts - Core Clock: 1168 / 1293 Boost / Memory Clock: 6712 MHz
http://www.guru3d.com/articles_pages/nvidia_geforce_gtx_750_and_750_ti_review,22.html
http://www.guru3d.com/articles_pages/nvidia_geforce_gtx_750_and_750_ti_review,22.html
So if there's a reason why the Asus and Gigabyte cards need the power connector, I certainly can't say because it offers some benefit in overclocking....the overclocks were virtually identical....and note Guru3D's comments regarding the windforce w/ the power connector
With the physical board power limit you are going see all cards roughly ending at this overclock and boost frequency.
I'd love to see someone do an updated article on the subject .... haven't seen one since 2009-10