Which model of Gtx 970 is good?

Your question is most certainly a valid one, all GFX cards are certainly not "created equal". There are significant differences in the vendor's investment in the quality of components used, whether or not they use custom or reference PCBs / VRMs, and how they go about cooling the VRMs and memory chips. **This** accounts for the difference in performance between the cards.

Choice most often comes down to "brand loyalty" but if you search around, you will find sites that do decent tear down articles which will allow you to make informed decisions. If you look at most sites, the Gigabyte G1 and MSI Gaming take the overclocking crowns with highest performance but most sites don't explain why. This one does, detaiiling all the physical differences between the cards:

Asus http://www.bit-tech.net/hardware/graphics/2014/09/19/nvidia-geforce-gtx-970-review/2

On its custom PCB, ASUS places all eight Samsung memory chips on the front side, meaning that the backplate does not directly cool any of them. In fact, the chips are left without any contact plate or heatsink touching them, relying solely on air from the fans to cool them.

We also find a 6-phase power delivery system for the GPU, a 50 percent upgrade from stock specifications. It also uses ASUS's DIGI+ VRM controller for precise, digital voltages, as well as high quality Super Alloy Power components for buzz-free choke operation, longer capacitor lifespan and MOSFETs with a 30 percent higher voltage threshold than standard. Sadly, the memory has not been granted the same treatment. It is fed by a single phase found at the other side of the PCB, and this one does not use any special components.

The MOSFETs of the DIGI+ power phases are cooled by a small heatsink, but the VRM controller and the MOSFETs for the memory power phase are left, like the memory chips, to fend for themselves without direct cooling.

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EVGA - http://www.bit-tech.net/hardware/graphics/2014/09/19/nvidia-geforce-gtx-970-review/3

One thing the ACX2 cooler does lack is a semi-passive mode. Even when idle, the fans will be spinning, which is not the case with the ASUS or MSI models. Both fans are also controlled by the same 4-pin header so there's no independent control.

EVGA sticks with the reference power input design, equipping the GTX 970 SC ACX2 with dual 6-pin power connectors. Examining the PCB reveals a 4+2 phase power design – four phases near the rear I/O for the GPU, and two in the bottom right corner for the memory. This is a slight upgrade from the 4+1 stock specification but unlike MSI and ASUS, EVGA does not use any specially crafted components.

The GPU MOSFETs are directly cooled by the main heatsink, which has a thermal strip on to draw heat up into the fin stack. On the other side of the GPU is a metal contact plate that partially cools two of the four memory chips on this side, leaving the other two exposed. It also cools the MOSFETs of the power phases serving the memory, but no thermal pads are used, so heat transfer is likely to be limited.

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MSI - http://www.bit-tech.net/hardware/graphics/2014/09/19/nvidia-geforce-gtx-970-review/3

Like the ASUS card, the GTX 970 Gaming 4G features a semi-passive mode, which it calls Zero Frozr. It's something MSI first brought to the market in 2008 (it's keen to clarify that it hasn't copied the ASUS Strix cards here). The temperature cut-off points are similar to the ASUS card – between 60 and 65°C, the fans will spin up; once the GPU drops to about 50°C, they're no longer needed. This carries benefits for noise production, efficiency and fan lifespan.

Another feature is called Hybrid Frozr, and this refers to the ability to control both fans independently. Enabling this functionality is a six-pin fan header on the PCB. In automatic mode, one fan is controlled by the GPU temperature while the other is controlled by temeprature measurement ICs dotted around the PCB. MSI claims it can result in a 1.9dB(A) noise reduction, and also offers users the ability to control the two fans independently using its Gaming App.

The power delivery is the best of any here; it's a 6+2 design. Further, MSI uses its own improved components for both the GPU and the memory power phases. The components are referred to as Military Class 4 since they meet MIL-STD-810G regulations. Specifically, we find Hi-c CAP and Solid CAP type capacitors and Super Ferrite Chokes, which are designed to provide higher stability, lifespan and efficiency.

A miniature heatsink takes care of cooling the main GPU MOSFETs near the rear I/O, while a metal contact plate equipped with thermal pads is used to cool three of the four front PCB memory chips as well as the remaining power circuitry including the memory MOSFETs and the VR controllers.

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Unfortunately, the Gigabyte G1 isn't in the review. The site ranked them MSI > Asus > EVGA, not surprising since the EVGA SC series has always been just a reference PCB with a different cooler and therefore really should not be judged in the same class as the custom PCB models from Asus, Gigabyte and MSI.

Another thing to consider is the feed back provided by users who actually own the card and how many really, really dissatisfied by looking at the number of extremely negative (1 egg) newegg user reviews:

Asus - Last place finisher in the popularity contest w/ 320 reviews, 8% gave it 1 egg
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121899

EVGA - comes in a bit back of the top 2 with 346 reviews, 8% were 1 egg
http://www.newegg.com/Product/Product.aspx?Item=N82E16814487076

Gigabyte - comes in 2nd in popularity with 439 reviews but a whopping 22% 1 eggers
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125684

MSI - 471 reviews make it the most popular model, with just 6% giving it 1 egg
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127832


As for MoBos, I have got no use for "tier" lists as the rankings don't, to my eyes, include many of the parameters I consider important, the main of which is performance, 2nd of which is how many regret their purchase.

Here's the performance rankings from Overclock3D site which actually tests the Gaming performance of Motherboards. In the table below, we added up the fps in each game they tested and the board with the highest total was given 100% ... the other boards are shown with respect to how ell they did compared to the fastest board

MSI Z97 Gaming 9 - 100.00%
MSI Z97 Gaming 5 - 99.86%
MSI Z97A Gaming 6 - 98.96%
Asus Z97 TUF Sabranco - 96.13%
Gigabyte Z97X Gaming 5 - 95.00%
Gigabyte Z97X SOC Force - 94.95%
Asus Z97 Maximus VII Hero - 93.67%
Asus Z97 Maximus VII Formula - 93.58%
Asus Z97 Maximus VII Gene - 91.69%
Asus Z97-A - 89.57%
MSI Z97 Mpower MAX AC - 88.20%
MSI Z97S SLI - 71.01%



Of the bunch, and taking price into account, I recommend the MSI Gaming 5 and the Gigabyte Gaming 5 ... love the look and quality of the Sabranco tho.

Ranked by Best Boards to Avoid based upon the number of extremely negative newegg reviews, here are the boards listed from worst to best:

Negative 1 Egg Reviews

Gigabyte Z97X SOC Force - 29% http://www.newegg.com/Product/Product.aspx?Item=N82E16813128704
MSI Z97 Gaming 9 - 28% http://www.newegg.com/Product/Product.aspx?Item=N82E16813130808
Asus Z97-A - 27% http://www.newegg.com/Product/Product.aspx?Item=N82E16813132118
Asus Z97 Maximus VII Formula - 26% http://www.newegg.com/Product/Product.aspx?Item=N82E16813132247
Asus Z97 Maximus VII Hero - 19% http://www.newegg.com/Product/Product.aspx?Item=N82E16813132125
MSI Z97S SLI 19% http://www.newegg.com/Product/Product.aspx?Item=N82E16813130801
Gigabyte Z97X Gaming 5 - 14% http://www.newegg.com/Product/Product.aspx?Item=N82E16813128709
MSI Z97A Gaming 6 - 12% http://www.newegg.com/Product/Product.aspx?Item=N82E16813128709
Asus Z97 Maximus VII Gene - 11% http://www.newegg.com/Product/Product.aspx?Item=N82E16813132136
MSI Z97 Gaming 5 - 10% http://www.newegg.com/Product/Product.aspx?Item=N82E16813130770
MSI Z97 Mpower MAX AC - 4% http://www.newegg.com/Product/Product.aspx?Item=N82E16813130765
Asus Z97 TUF Sabranco - 3% http://www.newegg.com/Product/Product.aspx?Item=N82E16813132414

Sometimes the choices are tough as when the 1st place performance finisher, MSI Gaming 9 is 2nd on te best boards to avoid list with 28% having an extremely negative outlook on their puyrchase. Other times, with say the Asus Hero, Formula and Z97-A, they are both low on the performance ranking and high on the "I bought and I'm unhappy" ranking.

At $135 - $150, therefore I like the Gaming 5
At $250 - $275, I like the Asus Sabertooth Sabranco