Reducing table size during initial load with ADR in SQL Server
I don't see any significant difference in this test.

create database nonadr
ALTER DATABASE nonadr SET ACCELERATED_DATABASE_RECOVERY = OFF

create database adr
ALTER DATABASE adr SET ACCELERATED_DATABASE_RECOVERY = ON;

go

with q as
(select top (1000*1000*10) *
 from sys.messages m, sys.objects o
)
select *
into nonadr.dbo.test
from q;


with q as
(select top (1000*1000*10) *
 from sys.messages m, sys.objects o
)
select *
into adr.dbo.test
from q;

go

exec nonadr.sys.sp_spaceused 'test' 
exec adr.sys.sp_spaceused 'test'

SELECT DB_NAME(database_id) AS database_name,
       (persistent_version_store_size_kb / 1024.) AS persistent_version_store_size_mb
FROM sys.dm_tran_persistent_version_store_stats
WHERE persistent_version_store_size_kb &gt; 0;


outputs

name                 rows                 reserved           data               index_size         unused
-------------------- -------------------- ------------------ ------------------ ------------------ ------------------
test                 10000000             3352392 KB         3351944 KB         8 KB               440 KB

name                 rows                 reserved           data               index_size         unused
-------------------- -------------------- ------------------ ------------------ ------------------ ------------------
test                 10000000             3494856 KB         3494384 KB         8 KB               464 KB

database_name        persistent_version_store_size_mb
-------------------- ---------------------------------------
adr                  0.070312