I know this topic has been discussed many times before, but I spent the weekend testing various different items under different conditions and wanted to share some item recommendations. Each of the items was tested on an Iron Golem with 1 hard point in IG and 20 hard points in Golem Mastery. I ran Chaos Sanctuary and the Worldstone Keep in /players8 with a level 99 Necromancer with close to ideal gear as I see it with each of these items in my Golem. I also tested some others, but they weren't as good so they didn't make the list (crescent moon and last wish are examples). I also only include weapons in the list, so arguably good options like Exile are not there. Every item tested, was upped to it's elite base and ethereal where possible with perfect rolls. There may be items I didn't consider, so let me know if you like something I don't know.

Maxed Skellis + Mastery, Maxed CE. Used Amp Damage exclusively. This left 24 skill points unused and can be yours to make whatever flavor of fish you prefer.

I don't really want this thread to focus on the necromancer's gear, but I'm including it for the sake of completeness and reproducibility. The main focus was getting both Beast and 125 fcr in the same build. If you go for Beast and 75 fcr, you will have different stats, higher skill points and cheaper and/or easier to find gear choices. This shouldn't impact the specific choice of item for the golem though.

Beast + 125 fcr
Head: Circlet with 20 fcr, strength, all res and +2 to necro skills
Chest: Enigma in a Mage Plate base.
W/S 1: Beast Berserker Axe + Spirit
W/S 1: CTA Crystal Sword + Spirit
Neck: Crafted 20fcr, all res, strength, +2 all skills
Ring1: Stone of Jordan
Ring2: 10 fcr, all res, strength, mf
Belt: Arachnid
Gloves: Trang
Boots: Marrowwalk
Charms: Perfect Torch + Anni

Beast + 75 fcr
Head: Shako
Chest: Enigma in a Mage Plate base.
W/S 1: Beast Berserker Axe + Spirit
W/S 1: CTA Crystal Sword + Spirit
Neck: Maras
Ring1: Stone of Jordan
Ring2: Stone of Jordan
Belt: Arachnid
Gloves: Trang
Boots: Marrowwalk
Charms: Perfect Torch + Anni

With Beast in hand, your level 9 fanaticism affects your merc's ias breakpoint tables / function.

Act 2 Might Merc gear:
eth Andariel's with cham
Fortitude in eth AP Base
Infinity in eth Giant Thresher

With the -10 WSM of Giant Thresher and the 29 IAS from fanaticism, the merc reaches the 4.5 tick breakpoint with just 20 IAS from andys. This means 4.54 attacks per second. Lots of CB and LL. You can put whatever you want in your andariel's and maybe you want to go for a different gear setup entirely. Again, this shouldn't affect the choice of Golem item as long as you have Infinity. No golem will ever match the killing power of your merc, so the merc will always be the one to produce your first body to CE. They should be built to hit hard and not die.

So from now on, we have Might, Conviction and Fanaticism acting on our summons. These boost the damage, chance to hit and IAS (but not the pause between animations common to all necro minions).

From testing, it became obvious that focusing on the IAS breakpoints of the golem is secondary to other stats like CB. However, here they are and I will use them when discussing each item. It should be noted, the faster the minions attack the faster they'll get out their damage when you telestomp something.



EAIS = sIAS - WSM + (120*IAS)/(120+IAS)

Using Beast, unless you are grouped with someone who has access to a higher level of fanaticsm, sIAS = 29.

So now the golem donor items, from most affordable to most expensive and not necessarily in order of effectiveness. I've crossed out stats that the Golem does not receive and highlighted the ones that make the weapon stand out IMO. Some weapons can be ethereal, which makes a translucent golem and adds some damage. Good sockets include ias/allres jewels, eth and um runes. Um can add bleed to stop boss regen, which you don't get from any other source in my setup.


Immortal King Maul
2 sockets
+40% Increased Attack Speed
+200% Damage Against Demons
+200% Damage Against Undead
+35-40% Chance of Crushing Blow
+200% Enhanced Damage

With WSM of 10 and 40 IAS out of the box, we get access to the 10 frame animation. With 2 open sockets, you have the option to get to the 9 frame animation if you add 30 more IAS.
You get this item for Pgems and it comes in an elite base with 2 open sockets for cheap jewels or runes.


Windhammer
+180-230% Enhanced Damage
50% Chance of Crushing Blow
+60% Increased Attack Speed
33% Chance to cast level 22 Twister on striking

With WSM of 10 and 60 IAS, this weapon falls into the 10 frame animation. If you socket it with a shael or IAS jewel, you'd get to the 9 frame animation.
This item has access to high CB and the twisters which act as an AoE interrupt and trigger frequently and comes in an elite base. This item can be ethereal.




The Cranium Basher
+200-240% Enhanced Damage
Adds 20 Min & Max damage
+25 to Strength
20% Increased Attack Speed
Indestructible
All Resistances +25
75% Chance of Crushing Blow
4% Chance to cast level 1 Amplify Damage on striking

This slow weapon with WSM of 20 and 20 IAS results in a 12 frame animation. If you socket a shael or IAS jewel, it jumps to 11 frames.
Your golem gets very good CB and all res, making this a good option in an elite base. The all res, combined with a 15IAS/15 all res jewel and summon resists would give you a golem with 100 to all elemental resistances and 75% CB. As a Necro CtC amp damage is superfluous.


The Minotaur
+140-200% Enhanced Damage
Adds 20-30 Damage
Hit Blinds Target +2
Half Freeze Duration
+15-20 to Strength
Slows Target by 50%
30% Chance of Crushing Blow

Another slow weapon with WSM and 0 IAS. This results in a 13 frame animation, which can be improved to 12 with an IAS jewel or 11 with a Shael. It can be ethereal.
This weapon combines slow with CB making your golem perform similar to a clay golem. To get the most out of it, you'll need to upgrade and socket it, which adds to to total cost.
What's also cool about the Minotaur, is blind target comes with an animation, so you know where your golem is and what he is hitting and when the slow is applied. Blind seems to be removed by amplify damage and vice versa. While the slow affects champions and uniques, I didn't see the animation for blind target.




Kelpie Snare
+140-180% Enhanced Damage
Adds 30-50 Damage
Slows Target by 75%
Fire Resist +50%
+1.25 Life per Clvl
+10 to Strength

Base WSM is 0 and so is IAS. This means 12 frames per attack. 11 with a 15 IAS jewel and 10 with a Shael. It can be ethereal.
This item is basically useful for the slow it provides. However, without any CB you're basically getting a clay golem with a different sprite. With 20 points in Golem Mastery and 1 point in Clay Golem and 1 in Golem Mastery, the Clay Golem has 50% more HP, but lower damage, attack speed and a lesser slow. To get the most out of it, you'll need to upgrade and socket it, which adds to to total cost.
Kelpie didn't trigger any animation like Minotaur did, when I used it.


Hone Sundan
3 sockets
+160-200% Enhanced Damage
Adds 20-40 damage
45% Chance of Crushing Blow
Repairs 1 durability in 10 seconds

Base WSM is 0 and so is IAS. This means 12 frames per attack. With a single shael, you get the 10 frame animation. By adding a minimum of 45 IAS through sockets, you can reach 9 frames. This is the fastest my table goes, but in d2r it might be possible to reach higher frames than in d2lod. It can be ethereal.
It has descent CB and if you aren't too worried about the ED, can be quite cheap. However to make the most of it, you'll want it upp'd, eth and with good ED which means you're now competing with common mercenary equipment. With 3 sockets out of the box, there's a lot of room for customization. In my test I went with Shael Eth Um.


Obedience
30% Chance To Cast Level 21 Enchant When You Kill An Enemy
+40% Faster Hit Recovery
+370% Enhanced Damage
-25% Target Defense
Adds 3-14 Cold Damage (3 Seconds Duration,Normal)
-25% To Enemy Fire Resistance
40% Chance of Crushing Blow
+200-300 Defense (varies)
+10 To Strength
+10 To Dexterity
All Resistances +20-30 (varies)
Requirements -20%

With no way of increasing IAS we can only play with the WSM via the base we choose. WSM = 10, frame = 13; WSM = 0, frame = 12; WSM = -10, frame = 11. Since we have good CB with Obedience, go with the Giant Thresher or another -10 base.
What makes obedience stand out is the same reason why many people like it for a mercenary. CtC enchant, which will improve your Golem's CtH and therefore it's chance to proc CB. It also has - %target defense that does the same. With a good roll on all resistances, your golem will have around 95% resistances to all elements.
If you use a demonlimb on your golem, the enchant won't be as beneficial, but might save you some igg on repairs.

Insight
Level 12-17 Meditation Aura When Equipped
+35% Faster Cast Rate
+200-260% Enhanced Damage (varies)
+9 To Minimum Damage
180-250% Bonus to Attack Rating
Adds 5-30 Fire Damage
+75 Poison Damage Over 5 Seconds
+1-6 To Critical Strike
+5 To All Attributes
+2 To Mana After Each Kill
23% Better Chance of Getting Magic Items

With no way of increasing IAS we can only play with the WSM via the base we choose. WSM = 10, frame = 13; WSM = 0, frame = 12; WSM = -10, frame = 11. If you're min maxing I leave it to you to think about how much attack speed and damage matter for an IG, but I personally find them not to be my main objective.
Insight does little for the golem, but it does supply it's master with all the mana they could ever want.


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Now for the items that hurt to lose because they aren't cheap.


Stormlash
+240-300% Enhanced Damage
+30% Increased Attack Speed
15% Chance to cast level 10 Static Field on striking
20% Chance to cast level 18 Tornado on striking
Attacker Takes Lightning Damage of 30
33% Chance of Crushing Blow
+3-9 Lightning Absorb
Adds 1-473 Lightning Damage

WSM -10 and 30 IAS out of the box means we're already at 9 frames which is the quickest the table I have goes. In D2R faster might be possible, but there's the 15 frame pause that can't be changed, so I don't think it's worth going for more.
This really cool weapon will turn your IG into a little storm. The proc on static field is decent and you get CB. I like it for it's flashiness, since it really gives the golem some character. It could be argued whether it's worth the cost of the item or the opportunity cost of using an item with higher CB though. Put an Eth or Um in it.




Pride
25% Chance To Cast Level 17 Fire Wall When Struck
Level 16-20 Concentration Aura When Equipped (varies)
260-300% Bonus To Attack Rating (varies)
+(1*Clvl)% Damage To Demons (Based on Character Level)
Adds 50-280 Lightning Damage
20% Deadly Strike
Hit Blinds Target
Freezes Target +3
+10 To Vitality
Replenish Life +8
(1.875*Clvl)% Extra Gold From Monsters (Based on Character Level)

With no way of increasing IAS we can only play with the WSM via the base we choose. WSM = 10, frame = 13; WSM = 0, frame = 12; WSM = -10, frame = 11. If you're min maxing I leave it to you to think about how much attack speed and damage matter for an IG, but I personally find them not to be my main objective.
What you get with Pride is the Concentration Aura and a cTc Firewall. I personally think that this isn't worth the cost unless you are filthy rich. Yes, your skeletons and mercenary will hit harder and be interrupted less, but your golem won't have any CB and will occasionally cause it's targets to shatter. Hammerdin is the most popular class by a mile, so if you're in a public game and playing with others, chances are there's one of them running around.


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Breaking the mold

If you give your golem either Infinity or Beast, your or your mercs setup can be improved. Both runewords make good donor items for your IG.

Infinity
50% Chance To Cast Level 20 Chain Lightning When You Kill An Enemy
Level 12 Conviction Aura When Equipped
+35% Faster Run/Walk
+255-325% Enhanced Damage (varies)
-(45-55)% To Enemy Lightning Resistance (varies)
40% Chance of Crushing Blow
Prevent Monster Heal
+(0.5*Clvl) To Vitality (Based on Character Level)
30% Better Chance of Getting Magic Items
Level 21 Cyclone Armor (30 Charges)

With no way of increasing IAS we can only play with the WSM via the base we choose. WSM = 10, frame = 13; WSM = 0, frame = 12; WSM = -10, frame = 11. Since we have good CB with Infitinity, go with the Giant Thresher or another -10 base.
Your Golem will be running around fast with decent DB and most importantly, it will have Conviction. This changes the axioms for you and your merc entirely. You could make your merc an absolute menace by giving it a high damage weapon like The Reaper's Toll or switch it up and get an Act I merc with Faith freeing you up to hold something besides Beast.

Beast
Level 9 Fanaticism Aura When Equipped
+40% Increased Attack Speed
+240-270% Enhanced Damage (varies)
20% Chance of Crushing Blow
25% Chance of Open Wounds
+3 To Werebear
+3 To Lycanthropy
Prevent Monster Heal
+25-40 To Strength (varies)
+10 To Energy
+2 To Mana After Each Kill
Level 13 Summon Grizzly (5 Charges)

Beast weapons are typically made in Berserker Axes, so if you're buying, those have a WSM of 0. With 40 IAS, this would mean 10 frames. If you put it in something a little faster like a War Spike or Cryptic Sword, you're gonna get the maximum 9 frames. Since resell value won't matter and you want to max the amount of CB procs per second, it could be argued that the best base is the fastest base.
Beast by itself isn't the ideal choice for the Iron Golem on it's own. However, by giving Beast to him, you will be able to carry another weapon boosting your skill points, FCR and other stats which could be beneficial to your troop over all. It's worth considering.


Let me know what you think!

This post was edited by katondaEU on Nov 15 2021 09:36am

the only stats that matter for the iron golem is the aura it can supply to your pets. Also make the runeword in the lowest attack base possible so that the iron golem doesn't die from the life tap bug (didn't test if it's still in d2r though)

While I agree that an item providing an aura, like infinity, pride or beast is likely the most beneficial effect an IG can have, I don't agree that it's the only stat that matters. IGs can supply Crushing Blow, Chance to Cast useful spells, Slow and Open Wounds for those of us not rich enough to use expensive runewords or in the early phases of a ladder when we're still gearing up. It's also debatable that any of the above-listed items would make for a better golem than a clay golem.

Edit:

It looks like the life tap bug persists in D2R. I wasn't aware of it.

https://us.forums.blizzard.com/en/d2r/t/iron-golem-bugs/42642

This post was edited by katondaEU on Nov 15 2021 09:04am

I have used Insight as iron golem, cheap base since the mana aura is nice when using CE in general. Works very nice and its cheap to replace if something happens.

not only is the iron golem slow but his consecutive attacks are slower from the AI delay so optimizing it is pretty pointless. Just make sure it doesnt die and give an aura to your team

That's unfortunate to hear. I haven't tested clay golem myself yet, so I can't speak to whether it is less delayed than IG. Maybe the processing improved with the port to d2r. Either way, sounds like a lot of my energy went into theory-crafting for something that is bugged into uselessness.

This post was edited by katondaEU on Nov 15 2021 09:18am

One thing that I like from pride IG is that the cTc Firewall when struck acts like a signal to teleport out your IG from a risky situation, it has enough hp to always tank enough hits for the firewall to be cast and for you to evalue if you need to save it from that or not.

And while is true that OW or CB are things that can be good to have, most of the time is not a work for the IG, a very cheap OW IG may be in consideration if you are a UT summoner since the CB is something that you are going to get from your revivals, for regular PvM it's all about the auras and the runeword you want to risk it.

Have you tried forgoing Pride and giving the golem Beast instead so you can use something like HotO?

Is my assumption correct that Conviction > Fanaticism > Concentration in terms of importance for summonmancer?

This post was edited by katondaEU on Nov 15 2021 09:29am

I'm using HotO anyway, damage wise the extra skills in HotO or the fana boost are mostly the same, I'm not doing UT with my summoner and it's the only place were fana really shines.

Chams runes are less useful than Ber runes and welding a Beast is also an option while you are not going to be weilding a pride, so making the IG from pride was a more logical choice, was "cheaper" and I still have the option to go Beast by myself if I want.

https://forums.d2jsp.org/topic.php?t=48460552&f=87&o=0

This is an old but very detailed guide that has some indeep talk about 75fcr/125fcr beast/hoto some IG and other interesting stuff for pure summoner.

EDIT: Yes infinity merc is the number one priority (other than enigma), between fana or con, it's really close, but like I said, having conc on your golem still opens you the option to have fana yourself, while having fana in your golem closes the door for having conc at any point.

This post was edited by Titus1986 on Nov 15 2021 09:37am

Thanks for the link. It's a really good read.

Is Infinity on Golem with Faith on Act I merc even worth testing? That was going to be the next thing I tried out, but I'm sure someone has done it before. I imagine the only time it's better is in situations where your merc can't get close, but that's what teleport is for.