Summon Item causes FPS drop

When summoning items, Even a single one, there is an unreasonable amount of lag, this remains until the item despawns or it's picked up.
The command used is simply /summon Item ~ ~ ~5. It can have any id or NBT tag and it's always the same. It doesn't matter if the command is used from the chat or a command block.
Dropping an item from the inventory does not produce the same effect.