I have a Dell Latitude E5540 system (i5-4300U CPU, 4GB RAM, Intel HD graphics; less than a year old) which has been running very slowly recently (as in: waiting for minutes to open Word document/web page). So I have wiped the system and installed a fresh version of Windows 7. However, the system is still very slow.
The Windows Performance Index gives 2,9 for Aero graphics and 1,9 for CPU. PassMark gives values that are far below comparable systems (279.7 overall, 394.1 CPU, 46.1 2D graphics, 224.5 memory; the lowest values for the same model with the same CPU and graphics are 5 to 10 times higher). 3D graphics and HDD results are fine. To make sure this isn't a Windows problem, I ran Phoronix on Ubuntu and also received very low results (RAMspeed SMP v3.5.0 (Integer): 2776.19; RAMspeed SMP v3.5.0 (Floating Point): 2321.41; C-Ray v1.1: 569.41; Apache Benchmark v2.4.7: 2059371).
However, Dell's own "My Dell" system test shows that the system passes all tests, as does Intel's processor Diagnostics Tool. On this basis, Dell support tells me this is not a hardware problem and they are won't take it as a warranty case.
Is there anything I can do to find the source of the problem, either to fix it myself or convince Dell to take it on?