High Memory Usage on AMD EPYC 7282 Compared to Intel Xeon E5-2630 v4 with .NET 8.0 #97126

Hello,

I'm currently working with .NET 8.0 and have encountered a peculiar issue related to memory usage across different CPU architectures. Here's the context:

Setup: Two batches of VPS, each running an identical number of ASP.NET Core instances with similar workloads.
CPUs: One batch uses Intel Xeon CPU E5-2630 v4, and the other uses AMD EPYC 7282.
Issue: I've observed a significant difference in memory usage between these two setups. The VPS with AMD EPYC 7282 shows almost full memory utilization right from the start, whereas the Intel Xeon E5-2630 v4 setup uses only about half of the available memory.
This difference is quite striking, and I'm trying to understand what might be causing it. I've attached a screenshot for reference.

Could this be related to how .NET 8.0 interacts with different CPU architectures, or is there another factor I should consider? Any insights or suggestions would be greatly appreciated.

Thank you for your time and assistance.

Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 40 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 24
On-line CPU(s) list: 0-23
Vendor ID: GenuineIntel
Model name: Intel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz
CPU family: 6
Model: 79
Thread(s) per core: 1
Core(s) per socket: 24
Socket(s): 1
Stepping: 1
BogoMIPS: 4399.99
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb r
dtscp lm constant_tsc arch_perfmon rep_good nopl xtopology cpu
id tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse
4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c
rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpci
d_single pti ssbd ibrs ibpb stibp fsgsbase tsc_adjust bmi1 hle
avx2 smep bmi2 erms invpcid rtm rdseed adx smap xsaveopt arat
umip md_clear arch_capabilities
Virtualization features:
Hypervisor vendor: KVM
Virtualization type: full
Caches (sum of all):
L1d: 768 KiB (24 instances)
L1i: 768 KiB (24 instances)
L2: 96 MiB (24 instances)
L3: 16 MiB (1 instance)
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-23
Vulnerabilities:
Gather data sampling: Not affected
Itlb multihit: KVM: Mitigation: VMX unsupported
L1tf: Mitigation; PTE Inversion
Mds: Mitigation; Clear CPU buffers; SMT Host state unknown
Meltdown: Mitigation; PTI
Mmio stale data: Vulnerable: Clear CPU buffers attempted, no microcode; SMT Hos
t state unknown
Retbleed: Not affected
Spec rstack overflow: Not affected
Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl and se
ccomp
Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer saniti
zation
Spectre v2: Mitigation; Retpolines, IBPB conditional, IBRS_FW, STIBP disab
led, RSB filling, PBRSB-eIBRS Not affected
Srbds: Not affected
Tsx async abort: Mitigation; Clear CPU buffers; SMT Host state unknown

Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 24
On-line CPU(s) list: 0-23
Vendor ID: AuthenticAMD
Model name: AMD EPYC 7282 16-Core Processor
CPU family: 23
Model: 49
Thread(s) per core: 1
Core(s) per socket: 24
Socket(s): 1
Stepping: 0
BogoMIPS: 5589.50
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_
opt pdpe1gb rdtscp lm rep_good nopl cpuid extd_apicid tsc_know
n_freq pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe
popcnt tsc_deadline_timer aes xsave avx f16c rdrand hyperviso
r lahf_lm cmp_legacy cr8_legacy abm sse4a misalignsse 3dnowpre
fetch osvw perfctr_core ssbd ibrs ibpb stibp vmmcall fsgsbase
tsc_adjust bmi1 avx2 smep bmi2 rdseed adx smap clflushopt clwb
sha_ni xsaveopt xsavec xgetbv1 clzero xsaveerptr wbnoinvd ara
t umip rdpid arch_capabilities
Virtualization features:
Hypervisor vendor: KVM
Virtualization type: full
Caches (sum of all):
L1d: 1.5 MiB (24 instances)
L1i: 1.5 MiB (24 instances)
L2: 12 MiB (24 instances)
L3: 384 MiB (24 instances)
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-23
Vulnerabilities:
Gather data sampling: Not affected
Itlb multihit: Not affected
L1tf: Not affected
Mds: Not affected
Meltdown: Not affected
Mmio stale data: Not affected
Retbleed: Mitigation; untrained return thunk; SMT disabled
Spec rstack overflow: Mitigation; SMT disabled
Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl and se
ccomp
Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer saniti
zation
Spectre v2: Mitigation; Retpolines, IBPB conditional, STIBP disabled, RSB
filling, PBRSB-eIBRS Not affected
Srbds: Not affected
Tsx async abort: Not affected

AMD EPYC 7282:

Intel(R) Xeon(R) CPU E5-2630 v4:

System Info:

Icon name: computer-vm
Chassis: vm
Machine ID: 502a92bb04b95032ffb20fa665850b69
Boot ID: 89f838f101f2406a9ebbf2f16888b6da
Virtualization: kvm
Operating System: Ubuntu 22.04.3 LTS
Kernel: Linux 5.15.0-91-generic
Architecture: x86-64
Hardware Vendor: QEMU
Hardware Model: Standard PC i440FX + PIIX, 1996