Why is GPU Power Limit not maxed by default?

[Shlutka]

I've been having FPS issues with GTA V. I'm running an R9 290, and an FX-8320 OC'd @ 4.6ghz. I read a thread here on Tom's Hardware where someone said to increase the power limit of the GPU to +25% in the over drive settings of the driver. I was surprised to see my FPS increase by almost 10%. I'd like to increase it to +%50, but I assume there has to be something bad about it? If someone could explain exactly what GPU Power Limit does, and what the ups and downs of it are. That would be great.

Thanks in advance!

 

[Cons29]

not familiar with the limit, but for sure there is a reason behind it. probably safety.
in engineering design, I think they always add 20% as tolerance

 

[JackNaylorPE]

http://www.guru3d.com/articles_pages/radeon_r9_290_review_benchmarks,30.html

We found a small tweak that will bring your boost frequency towards almost 1075 MHz stable. We applied:

Power Target 150%
GPU clock 1075 MHz
Memory clock 1350MHz (x4)
Voltage (no control ATM, not recommended due to heat levels eather)
Fan control RPM @ default

 

[JWoody]

Higher voltages usually result in better clock increases with auto-boost or overclocking, upping the power limit allows the card or software to up it voltages beyond the normal BIOS maximum defaults.

 

[renz496]

So why they are not max out from the get go? To give user untapped performance. Simple as that. Overclocking headroom has become part of marketing. This past few generations of gpu 'overclockers dream' already being part of nvidia and AMD power point slides.

 

[hang-the-9]

So why they are not max out from the get go? To give user untapped performance. Simple as that. Overclocking headroom has become part of marketing. This past few generations of gpu 'overclockers dream' already being part of nvidia and AMD power point slides.

It's more of an issue with stability and reliability than overclocking marketing. Plus there will be a lot more overlapping in products if the performance of the lower card in stock form was very close to a higher range card. Same reason the manufacturer suggested power requirements are about 20% over what you can run the card on. If something happens with the card when it's at the limit, they have to replace it, if they list a spec over or under the limit (in power and speeds), there is a larger leeway for a more stable product.

 

[renz496]

Well in the past i might take it like that. But ever since nvidia start imposing restriction to board partner about overclocking (or else they will lose warranty from nvidia) i do think nvidia leave some 'headroom' on purpose. I don't know about AMD but i think that's the case with nvidia.