2.6.18-164.el5xen is a kernel. The 2.6.18-164.el5xen has been tested via the Phoronix Test Suite in the configurations listed below.
centos01_test1 - Tests on CentOS 5.4, Intel Xeon 3.00GHz, XGI, Supermicro X7DVL-3
aaaa - Tests on CentOS 5.3, Intel Xeon 3.20GHz, ATI Rage XL
iozone-20100730 - Tests on Ubuntu 10.04, CentOS 5.4, Intel Core i7 870, NVIDIA GT200b, ASUS P7P55D-E PREMIUM, Intel Xeon E5620, Intel Eaglelake, Dell PowerEdge R610, AMD Phenom II X4 945, InnoTek VirtualBox, innotek VirtualBox
iozone-20100730 - Tests on Ubuntu 10.04, CentOS 5.4, Intel Core i7 870, NVIDIA GT200b, ASUS P7P55D-E PREMIUM, Intel Xeon E5620, Intel Eaglelake, Dell PowerEdge R610
vx-8gb-sg_Apr/22/2010_14:12 - Tests on CentOS 5.4, Intel Xeon L5520
vx-8gb-nl_Apr/22/2010_14:12 - Tests on CentOS 5.4, Intel Xeon L5520
vx-14gb-sg_Apr/22/2010_14:12 - Tests on CentOS 5.4, Intel Xeon L5520
vx-14gb-nl_Apr/22/2010_14:12 - Tests on CentOS 5.4, Intel Xeon L5520
vx-2gb-ny_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520
vx-4gb-ny_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520
vx-2gb-nl_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520
vx-4gb-nl_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520
vx-2gb-sg_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520
vx-4gb-sg_Apr/21/2010_02:14 - Tests on CentOS 5.4, Intel Xeon L5520