By looking at benchamarks both synthetic, real life, and gaming benchmarks, and how naming scheme shown improvements its easy to see, that Iris 6100 will be significantly faster than Iris Pro 1. HD5400 Should be faster than Iris Pro(HD5200). So its not so obvious .
Like ive said. Intel by trying to ditch the dGPUs from computers have 2 ways. Give a good solution of their own for iGPUs, and be at least comparable to current mid-end dGPUs, or... buying Nvidia. Second is really unlikely.
im 100% sure they could buy nvidia with ease as intel is worth around $90bn and nvidia around $4bn but i don't think the fcc will approve it because it may be looked as monopolizing , actually they should cause they would make a fantastic chip together and they actually have alot of chip competitors lol ; http://en.wikipedia.org/wiki/Semiconductor_sales_leaders_by_year