PC Buyer Beware!

How to find out if a PC provides particular graphics card support

How to find out if a PC’s motherboard and power supply provide graphics card support for an Asus Nvidia GeForce GTX 750 Ti card


My PC has a Gigabyte GA-H81M0-S1 motherboard. I need to know if it provides graphics card support for an Asus Nvidia GeForce GTX 750 Ti 2GB GDDR5 card, which I intend to buy if that is the case.


The following information can be applied to finding out what motherboard and power supply support is required to upgrade any graphics card.

Obtain the User Manual for your Gigabyte motherboard

Obtain the User Manual for your Gigabyte motherboard from its manufacturer’s website. All of the major motherboard manufacturers provide User Manuals for their models. It tells you almost everything you need to know about it and its UEFI BIOS, including the types of graphics card support. Get it here:


PCI Express 3.0 (PCI-E 3.0)

The Asus GeForce GTX 750 is a PCI  Express graphics card that supports the PCI-E 3.0 standard.

The GA-H81M-S1 motherboard does not support the PCI Express 3.0 (PCI-E 3.0) standard, only PCI Express 2.0. Fortunately, a PCI-E 3.0 card will run in a PCI-E 2.0 slot. There is no noticeable difference between the two standards. The two versions are 100% backward compatible. I had to look that information up because the User Manual did not provide it. See the list of the board’s specifications here:


VGA and DVI-D ports on the Nvidia GeForce GTX 750 Ti graphics card

The image, below, shows the graphics output VGA and DVI-D ports on the Nvidia GeForce GTX 750 Ti graphics card that connect it to a PC monitor. The single D-sub VGA output port is blue and the two DVI-D output ports are grey.

Asus Nvidia GeForce GTX 750 Ti graphics card’s single blue VGA and two grey DVI-D output ports

The GA-H81M-S1 motherboard only has a single PCI-E x16 slot for a graphics card

The GA-H81M-S1 motherboard, shown below, uses an onboard graphics chip and a D-sub VGA port to provide a display. It only has a single long PCI-E x16 slot for graphics card support and two short PCI-E x1 slots for other cards – the three vertical slots on the left hand side of the board. Fortunately, you can install both x8 and x16 graphics cards in a x16 slot.

Graphics card support – Gigabyte GA-H81M0-S1 motherboard – Single PCI-E slot for graphics card. Click on the image to view its full size

Graphics card support: How to disable the onboard graphics chip

Unless you want to run a monitor from both graphics ports, which is possible, you have to find out from the motherboard’s User Manual how to disable the onboard graphics chip. That information is usually in the UEFI BIOS section of the manual, as is the case with all Gigabyte motherboards. If you want to use two monitors you have to set one of them as the main monitor. Here is the setting information from the BIOS section of the User Manual:

GA-H81M-S1 motherboard UEFI BIOS – Peripherals

Initial Display Output
Specifies the first initiation of the monitor display from the installed PCI Express graphics card or the onboard
IGFX Sets the onboard graphics as the first display.
PCIe 1 Slot Sets the graphics card on the PCIEX16 slot as the first display. (Default)

Intel Processor Graphics
Enables or disables the onboard graphics function. (Default: Enabled)

Nvidia GeForce GTX 750 Ti graphics card requires a single 6-pin power-supply connector

The Specifications page on the Asus website tells you if the graphics card in question needs additional power supply connections from the power supply. It says: “Power Consumption – Up to 150W1 additional 6-pin PCIe power required.”

The specifications for that Asus graphics card are on this page:


The image below shows an AMD Radeon graphics card that requires the graphics card support of two additional 6-pin power connectors from the computer’s power supply unit (PSU). If your computer’s power supply does not provide a single 6-pin power connector, you can buy a Molex adapter cable that provides the connector. You connect the Molex end to a Molex power cable coming from the power supply and the other end plugs into the graphics card. Web-search for “molex to 6-pin pcie power adapter cable”.

High-end AMD Radeon graphics card that requires two additional power cables from the power supply unit

The power supply unit must also be able to provide enough power for the graphics card

Your computer’s power supply unit must also be able to provide enough power for the graphics card. Use this power supply calculator to find out if your power supply provides enough power.


The Asus version of this graphics card requires an additional 1x 6-pin PCI Express power cable from the power supply unit. The Zotac and Gigabyte versions of this card are powered via the PCI-E bus and so require no additional power connector(s).

Here are some helpful quotes from purchasers of this graphics card on Amazon:

“I’m running a Corsair 500W power supply and had no problems whatsoever.”

“I had a 500W PSU and the GPU didn’t work. It turned out that 550W did work. So, depending on what other components you have in your computer, you might get away with 500W, but it’s not a certainty.”

“I have it running happily with a 405W PSU, so 500W shouldn’t be a problem.”

Why the quality of the power supply unit is an important consideration

Note that brand-name power supplies of high quality, such as Corsair, deliver the total power that they advertise on the unit itself. Depending on which components use the power supply, it looks as if you can install that Asus graphics card on a computer with a 400W power supply if it is a quality unit. However, cheap power supplies that state that they can deliver a total of 400W usually cannot.

Always buy a quality brand-name power supply. Many brand-name PCs come with a cheap power supply. Web-search the name of the power supply that came with your new PC. If it gets bad comments or reviews, replace it with a quality unit. Remember that if the power supply blows it can take the other components with it and in rare case cause a fire.

About five years ago, I bought an Advent office PC that was powered by a cheap 400W power supply, so I switched it with a 400W Corsair power supply and it is still running now having only ever been switched off to service it.

Quality power supplies come with many protections that a cheap unit might not provide, such as these:

Over-Voltage Protection (primary and secondary)
Under-Voltage Protection (primary and secondary)
No-Load Operation
Short-Circuit Protection
Over-Current Protection
Overload Protection
Overheating Protection

Visit the Power Supply Units – PSUs section of this website for detailed information on them.