how many spawn blocks on gold farms to get the most of it

I am making a gold farm but I am wondering how many spawn blocks to get a nice efficiency.

I have now 2 towers each tower is 30 row each row is 22 spawn blocks that means 660 block per tower and 1320 in total

is the 1320 block is enough to get the max efficiency or I should add more ??

Ive been messing around with one and if you did something like 2 towers of 20x12 with 12 of those in a tower, thats about 6000

At that point, the majority of the efficiency comes from slabbing. You'll want to slab out several chunks in every direction from your "afk spot." Then if it's still not fast enough, you'll have to explore the nether and look for hidden caves and little nooks to slab as over time the pigmen spawn in them decreasing your gold per hour.

my slabbing is 5 chunks in every direction of the farm. is that enough for it ???

Yes thats fine

That should be fine. If you haven't though, explore a little more and look for those small caves up by the top or even the little tunnels/caverns along the floor.

But can the 1320 block get a nice amount of gold or just 16 ingot per hour ??

I don't know how many spawn pads Jc and I had, but it was probably similar to your 1320. We got 32ish Blocks per hour, so if you are only getting 16 ingots there's a huge chunk of slabbing you missed.

What i plan on doing is quarrying out 90x90 and building a combined wither / gold / blaze farm

I have spent a month on slabbing searching for every single cave to cover it. I don't think there is more caves

I don't know my efficiency yet. I am still building on it. It will work in few days. But i am afraid of it to be useless

If you've slabbed as you say you did, then you have nothing to fear.

Are you doing manual/automatic pick-up?

I am planning to make a hoppers system for collection to transfer it to chests