Lately I've launched a few EC2 c1.xlarge instances with identical setups to ones that I launch a few months ago and I've found that the new ones have 5-10 times the CPU usage. The only difference I can see is that new instances use a 6M cache. Has anyone else experienced this oddness? I've also noticed the new, slower ones have the sse4_1 flag, whereas the old, faster ones don't. Super confusing!
Here is the /proc/cpuinfo for the new, slower one:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz
stepping : 10
cpu MHz : 2327.506
cache size : 6144 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 1
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good aperfmperf pni ssse3 cx16 sse4_1 hypervisor lahf_lm
bogomips : 4657.88
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
And here it is for the old, faster one:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5345 @ 2.33GHz
stepping : 11
cpu MHz : 2327.502
cache size : 4096 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good aperfmperf pni ssse3 cx16 hypervisor lahf_lm
bogomips : 4662.14
clflush size : 64
cache_alignment : 64
address sizes : 38 bits physical, 48 bits virtual
Anyone have any idea what could be going on?