Nvidia LDAT & PCAT – What Are They?

What is Power Capture Analysis Tool (PCAT)?

All this talk of latency is one thing, but there’s an extra tool in this setup, and it’s called the Power Capture Analysis Tool or PCAT for short. It’s designed to measure graphics card power consumption more accurately than simply using a Watt meter on the mains plug and trying to work it out from the whole PC usage.

How it works is that it sits between the motherboard and graphics card, kind of like a riser cable, so it can measure the power drawn from the motherboard/PCIe lane. It’s compatible with any PCIe card up to and including PCIe Gen 4.

There’s also a 3-in-3-out PCB for the PSU power cables, which can again measure the throughput. There’s a small OLED display for on-the-fly monitoring too.

It’s an elegant system that can give you relatively real-time readouts of the 12v and 3.3v rails of your graphics card. Furthermore, it’s compatible with FrameView 1.1 software that you can use for LDAT, which can log the usage in relation to frame timing. Effectively, you can measure just how much power it takes to render a frame, and how that relates to FPS, latency and more.

As you can see, one is wired to the other with a simple cable. Then there’s a USB cable that can be plugged into the external PC you’re using to record the output data.

PCAT Software

There’s a simple software tool that does exactly what you would expect and gives you a numerical and graphical outlay of the information. It checks every 100ms for the power state, splits that over time, and logs the minimum, maximum and average power states.