They may all be there, but they may not work. At one point, the old Geforce 6800 cards came in three varieties. The cheapest model had two disabled functional

They may all be there, but they may not work. At one point, the old Geforce 6800 cards came in three varieties. The cheapest model had two disabled functional units. You could often unlock one successfully (6800XT to 6800), but both (6800XT to 6800GS) was prone to much higher instability and failure. Even if all the transistors worked, the rest of the board (power delivery, heatsinking) was often downgraded on cheap models.