Link to the EFcore repository issue dotnet/efcore#35053

Benchmark results

Get customer by id. Include orders. Include orderItems

Method	Job	Runtime	UseSplitQuery	Mean	Error	StdDev	Ratio	RatioSD	Allocated	Alloc Ratio
GetCustomerById	.NET 8.0	.NET 8.0	False	1.688 ms	0.0368 ms	0.1038 ms	1.00	0.09	53.82 KB	1.00
GetCustomerById	.NET 9.0	.NET 9.0	False	2.516 ms	0.0474 ms	0.1059 ms	1.50	0.11	196.56 KB	3.65
GetCustomerById	.NET 8.0	.NET 8.0	True	2.867 ms	0.0598 ms	0.1705 ms	1.00	0.08	79.58 KB	1.00
GetCustomerById	.NET 9.0	.NET 9.0	True	3.114 ms	0.0732 ms	0.2136 ms	1.09	0.10	161.05 KB	2.02

Get customer by id

Method	Job	Runtime	Mean	Error	StdDev	Ratio	RatioSD	Allocated	Alloc Ratio
GetCustomerById	.NET 8.0	.NET 8.0	765.2 us	14.68 us	35.16 us	1.00	0.06	13.09 KB	1.00
GetCustomerById	.NET 9.0	.NET 9.0	734.8 us	14.44 us	17.73 us	0.96	0.05	14.59 KB	1.12
GetCustomerByIdDapper	.NET 8.0	.NET 8.0	620.8 us	14.45 us	41.68 us	1.00	0.09	4.95 KB	1.00
GetCustomerByIdDapper	.NET 9.0	.NET 9.0	592.3 us	11.28 us	18.22 us	0.96	0.07	4.96 KB	1.00

Get all customers ids (there are 10000 in total)

Method	Job	Runtime	Mean	Error	StdDev	Ratio	RatioSD	Allocated	Alloc Ratio
GetCustomersIds	.NET 8.0	.NET 8.0	2.853 ms	0.0363 ms	0.0340 ms	1.00	0.02	2380.84 KB	1.00
GetCustomersIds	.NET 9.0	.NET 9.0	2.789 ms	0.0530 ms	0.0650 ms	0.98	0.03	2381.85 KB	1.00
GetCustomersIdsDapper	.NET 8.0	.NET 8.0	2.565 ms	0.0503 ms	0.0471 ms	1.00	0.03	981.21 KB	1.00
GetCustomersIdsDapper	.NET 9.0	.NET 9.0	2.492 ms	0.0367 ms	0.0343 ms	0.97	0.02	981.64 KB	1.00

Get customers count

Method	Job	Runtime	Mean	Error	StdDev	Allocated
GetCustomersCount	.NET 8.0	.NET 8.0	955.3 us	11.84 us	11.08 us	4.97 KB
GetCustomersCountDapper	.NET 8.0	.NET 8.0	924.6 us	10.75 us	10.06 us	2.13 KB
GetCustomersCount	.NET 9.0	.NET 9.0	939.0 us	6.70 us	5.94 us	5.56 KB
GetCustomersCountDapper	.NET 9.0	.NET 9.0	919.2 us	12.36 us	11.56 us	2.17 KB

Load Test Results Summary

Comparing the performance metrics for .NET 8 and .NET 9:

Metric	.NET 8	.NET 9
Total Requests	1,690,574	1,287,101
Requests per second	1,741.02	1,325.61
Data Received	13 GB	9.5 GB
Data Sent	220 MB	164 MB
HTTP Request Duration	avg=2.29s, p(90)=4.79s, p(95)=5.51s	avg=3.32s, p(90)=6.73s, p(95)=8.06s
Request Blocking	avg=6.02µs, p(90)=5.01µs, p(95)=5.81µs	avg=6.65µs, p(90)=5.15µs, p(95)=6.02µs
Request Receiving	avg=44.14µs, p(90)=61.38µs, p(95)=75.48µs	avg=42.62µs, p(90)=62.5µs, p(95)=76.01µs
Request Sending	avg=14.77µs, p(90)=16.12µs, p(95)=32.88µs	avg=13.8µs, p(90)=15.95µs, p(95)=29.79µs
Iteration Duration	avg=3.29s, p(90)=5.79s, p(95)=6.52s	avg=4.32s, p(90)=7.73s, p(95)=9.06s
Virtual Users (VUs)	max=10,000	max=10,000

To visualize these differences, here’s a comparative analysis:

This summary highlights key performance metrics, demonstrating how both .NET versions handle load testing. From the given data, we can see that .NET 8 had a higher throughput (Requests per second) and better average request duration compared to .NET 9.