After moving PC's from Cat5509 with x5225 modules to Cat4006 with X4148 inline power modules collision errors occur to the eventual detriment of the PC. Company standard port config is 10/half duplex. No errors were evident when attached to Cat5k 10/half duplex. When set to FULL duplex, errors decrease and performance of PC is maintained.
Can anyone advise why the PC's are 100% when attached to Cat5K but not 100% when attached to Cat4K and why changing to FULL duplex should have such an impact?