▁a ▁Linux - based ▁development ▁platform ▁to ▁help ▁developers ▁program ▁for ▁Cell ▁ch ips . ▁ ▁History ▁ ▁In ▁mid - 2 0 0 0 , ▁Sony ▁Computer ▁Entertainment , ▁T os hib a ▁Corporation , ▁and ▁IBM ▁formed ▁an ▁al liance ▁known ▁as ▁" ST I " ▁to ▁design ▁and ▁manufact ure ▁the ▁processor . ▁ ▁The ▁ST I ▁Design ▁Center ▁opened ▁in ▁March ▁ 2 0 0 1 . ▁The ▁Cell ▁was ▁designed ▁over ▁a ▁period ▁of ▁four ▁years , ▁using ▁en hanced ▁versions ▁of ▁the ▁design ▁tools ▁for ▁the ▁P OW ER 4 ▁processor . ▁Over ▁ 4 0 0 ▁engine ers ▁from ▁the ▁three ▁companies ▁worked ▁together ▁in ▁Austin , ▁with ▁critical ▁support ▁from ▁eleven ▁of ▁IBM ' s ▁design ▁cent ers . ▁During ▁this ▁period , ▁IBM ▁file d ▁many ▁pat ents ▁per tain ing ▁to ▁the ▁Cell ▁architecture , ▁manufact uring ▁process , ▁and ▁software ▁environment . ▁An ▁early ▁pat ent ▁version ▁of ▁the ▁Broad band ▁Engine ▁was ▁shown ▁to ▁be ▁a ▁chip ▁package ▁compr ising ▁four ▁" Process ing ▁Element s ", ▁which ▁was ▁the ▁pat ent ' s ▁description ▁for ▁what ▁is ▁now ▁known ▁as ▁the ▁Power ▁Process ing ▁Element ▁( P PE ). ▁Each ▁Process ing ▁Element ▁contained ▁ 8 ▁A PU s , ▁which ▁are ▁now ▁referred ▁to ▁as ▁S PE s ▁on ▁the ▁current ▁Broad band ▁Engine ▁chip . ▁This ▁chip ▁package ▁was ▁widely ▁regarded ▁to ▁run ▁at ▁a ▁clock ▁speed ▁of ▁ 4   G Hz ▁and ▁with ▁ 3 2