Introduction

Last month, NVIDIA released the GeForce GTX 1660 Ti and with it split its client-segment discrete graphics lineup into the GeForce GTX series and GeForce RTX series. The RTX 20-series starts at the $350-mark with the RTX 2060, while models below it are relegated to the GTX brand. The best part? Both are based on NVIDIA's latest 12 nm "Turing" architecture. What sets the two apart is right in the name—RTX real-time raytracing technology.

NVIDIA probably figured that getting RTX to work even at 1080p requires a minimum number of RT cores and CUDA core horsepower, which cannot be scaled down beyond a certain point because enabling RTX features already exacts a roughly 30 percent performance tax, and NVIDIA wouldn't want $200–$300 graphics cards being unable to play RTX-enabled games at 1080p with acceptable frame rates. The RTX 2060 appears to be positioned on that limit. In games without raytracing, the RTX 2060 has enough muscle for 1440p resolution, but on games with RTX-enabled, playability swings halfway between 1080p and 1440p.

The easiest way out of this problem for NVIDIA would be to not bother with RTX below the $350-mark and instead focus on making the GPU as cost efficient as possible. With RTX out of the way, NVIDIA could physically remove RT cores that add billions of transistors to the silicon, making the chips smaller. Interestingly, NVIDIA also decided to axe tensor cores, specialized hardware that accelerate deep-learning neural net building and training, shedding even more transistor load. The remaining CUDA cores are very much from the "Turing" architecture and benefit from the increased IPC and higher clock-speed headroom obtained from the switch to 12 nm. The largest such GTX Turing chip is the new "TU116". The second TU116-based card was announced very recently with the GTX 1660 (non-Ti).



NVIDIA carved the GTX 1660 out of the "TU116" silicon by disabling 2 out of 24 streaming multiprocessors, resulting in a CUDA core count of 1,408 and 88 TMUs, which is still higher than what the "Pascal" based GTX 1060 6 GB packs. With 48 ROPs and a 192-bit GDDR5 memory bus driving 6 GB of memory, the rendering and memory subsystem is practically carried over.

Today, we're reviewing the ASUS GeForce RTX 1660 Ti STRIX OC, which is the company's premium offering based on this GPU, featuring a large triple-fan, triple-slot cooler, RGB support, dual BIOS, a metal backplate and an overclock out of the box. Seems the ASUS STRIX ticks all the feature checkboxes, but it isn't cheap at $330.

Packaging and Contents

You will receive:

• Graphics card
• Documentation
• Driver disc
• ASUS zip ties

The Card

The ASUS card follows the theme set by their previous GeForce 20 cards. A backplate is included, too. Dimensions of the card are 30.0 x 13.0 cm.


Installation requires three slots in your system.


Display connectivity options include two standard-size DisplayPort 1.4a and two HDMI 2.0b.

NVIDIA has updated their display engine with the Turing microarchitecture, which now supports DisplayPort 1.4a with support for VESA's nearly lossless Display Stream Compression (DSC). Combined, this enables support for 8K@30Hz with a single cable, or 8K@60Hz when DSC is turned on. For context, DisplayPort 1.4a is the latest version of the standard that was published in April, 2018.

At CES 2019, NVIDIA announced that all their graphics cards will now support VESA Adaptive Sync (aka FreeSync). While only a small number of FreeSync monitors have been fully qualified for G-SYNC, users can enable the feature in NVIDIA's control panel, no matter whether the monitor is certified or not.


The board uses a single 8-pin power connector. This input configuration is specified for up to 225 watts of power draw.


The GeForce GTX 1660 does not support SLI. Instead, ASUS used that area to place some additional features. The first (from the left) is the dual-BIOS switch that toggles between the default "performance" BIOS and "quiet" BIOS which comes with a more relaxed fan curve and includes idle-fan-stop, too. Moving further to the right, we see a big button used to turn off the RGB illumination of the card completely (until next reboot). The solder pads further to the right are used for voltage measurement and tweaking.


Unfortunately, ASUS didn't label these points, probably to ensure they won't get into trouble with NVIDIA.


In addition to that, a bunch of nicely labeled solder pads were added to measure various voltages directly.


You also get two 4-pin PWM fan headers to sync your case fan to the graphics card's fans and an addressable RGB header to connect other RGB components.

Disassembly

The large ASUS heatsink uses three double-length heatpipes to keep the card cool.


Once the main cooler is removed, a black die-cast baseplate becomes visible. It covers most of the card and provides cooling for memory chips and VRM circuitry.


The backplate is made out of metal and protects the card against damage during installation and handling.

On the next page, we dive deep into the PCB layout and VRM configuration.

High-resolution PCB Pictures

These pictures are for the convenience of volt-modders and those who would like to see all the finer details on the PCB. Feel free to link back to us and use them in your articles or forum posts.



High-res versions are also available (front, back).