DIRECTX 12 AND 12_1: WHAT’S THE DIF­FER­ENCE?

HWM (Malaysia) - - LEARN - Ko­hWanzi

by Win­dows 10 is rolling out for free to PCs across the globe, and it's at the cen­ter of many things, not least Mi­crosoft's uni­ver­sal app strat­egy to grow the se­lec­tion of Win­dows Phone apps by get­ting de­vel­op­ers to cre­ate apps for Win­dows 10 desk­tops.

But there's one other rea­son why Win­dows 10 mat­ters, and that's DirectX 12. Touted as a next-gen­er­a­tion ap­pli­ca­tion pro­gram­ming in­ter­face (API) that of­fers lower over­heads and more ef­fi­cient uti­liza­tion of multi-core CPUs, DirectX 12 prom­ises im­proved per­for­mance for gamers all over.

That sounds great, which is why DirectX 12 has been the cen­ter of a lot of hype and also a lot of con­fu­sion. Con­sid­er­able dis­cus­sion has arisen around DirectX fea­ture lev­els and ver­sion num­bers, and you may have seen DirectX ref­er­enced var­i­ously as DirectX 11.1 and 12_1. As it turns out, that's not due to vary­ing house styles and the two are in fact quite dif­fer­ent things.

A DirectX ver­sion up­date adds a new set of stan­dard­ized ca­pa­bil­i­ties that give de­vel­op­ers more tools to do their jobs bet­ter. In the case

154

HWM

|

NOVEM­BER 2015 of DirectX 12, that would be the abil­ity to have lower API over­heads, im­proved uti­liza­tion of multi-core CPUs, and the abil­ity to com­bine the graph­ics pro­cess­ing ca­pa­bil­i­ties of non-iden­ti­cal GPUs.

On the other hand, a DirectX fea­ture level is a clearly de­fined set of GPU func­tion­al­ity. It de­fines the min­i­mum level of sup­port a par­tic­u­lar GPU needs to of­fer while still sup­port­ing the un­der­ly­ing DirectX spec­i­fi­ca­tion. Note that we said min­i­mum lev­els of sup­port, so even though fea­ture level 12_1 spec­i­fies sup­port for con­ser­va­tive ras­ter­i­za­tion Tier 1, a card like NVIDIA's GeForce GTX TI­TAN X ac­tu­ally sup­ports Tier 2.

Ul­ti­mately, de­spite their sim­i­lar­i­ties in nam­ing, fea­ture lev­els aren't re­ally re­lated to the DirectX 12 API, which is why a card that sup­ports only fea­ture level 11_1 can still sup­port DirectX 12.

Take the AMD Radeon R7 370 for ex­am­ple. Even though the card sup­ports only fea­ture level 11_1, it can still take ad­van­tage of the key ben­e­fits of DirectX 12 like more di­rect ac­cess to GPU hard­ware for the API. How­ever, it will not ben­e­fit from as­pects of fea­ture level 12_1 like vol­ume tiled resources and con­ser­va­tive raster.

DirectX fea­ture lev­els are pre-de­fined sets of GPU func­tion­al­ity.

Newspapers in English

Newspapers from Malaysia

© PressReader. All rights reserved.