The Intel Celeron B820 is a sandy bridge processor that is used in entry level notebooks like Acer Aspire E1, Gateway NE56R13u, Asus X54 CHB01 and so on. Like other sandy bridge processors, the B820 comes with Intel integrated graphics, which in this case is HD graphics 2000. This GPU runs at 650-1050MHz. There is no turbo boost so the CPU cannot overclock itself when required.
Some other power saving features also come deactivated. The Celeron B820 is a full voltage processor and has a TDP of 35 watts. We ran the passmark benchmark test on it and were able to get 1648 in the test.
To be honest, those scores are pretty much below average and at par with Celeron 867 (1241), Celeron 847 (949) and Celeron 877 (1470). That said, the Intel Celeron B820 does perform a tiny better than the original Intel B800 that got 1509 score in the passmark test.
Intel Pentium B950 and B940 got 1982 and 1978 respectively. The Intel Pentium B960 got 2080.