Sapphire has updated its range of Radeon RX 550 graphics card offerings with boosted amounts of active Stream Processors (SPs). If you head on over to the Sapphire product pages for the Pulse Radeon RX 550 4GD5 or Pulse Radeon RX 550 2GD5, then click the specifications tab you will be able to toggle the specs table shown between versions offering 512 SPs and 640 SPs. However, while the SP count has been significantly improved, other specs including the Boost Engine Clock and Memory Clock have been reduced.
Fellow tech site TechPowerUp brought the changes to light and notes that the new RX 500 cards with 640 SPs are based upon Polaris 21, rather than the Polaris 20 upon which their brethren are based. AMD bases its RX 560 designs upon the Polaris 21 but again has models with varying amounts of SPs depending upon model number.
Below I have reproduced the specs tables of the Sapphire Pulse Radeon RX 550 2GD5 based upon both the Polaris 21 and Polaris 20, so you can see the other changes accompanying the SP count change. Except for the amount of RAM on board the 2GB and 4GB variants offer the same engine/memory clocks.
With various specs moving up and others down the end result is likely to be a card offering very similar performance to the existing RX 550 offerings otherwise there would have been some kind of publicity for this change and/or a naming change like ‘RX 550+’ of similar. With their 200MHz slower default Boost Engine Clocks the new 640 SPs RX 550 cards could well offer improved OC headroom though.