Lian Li A4-H2O Mini-ITX PC Case, Triple-Slot Mount GPU, Aluminum Exterior & SPCC Steel Interior, 240mm AIO, SFX Sandwich Layout, PCIe 4.0, Supports SFX/SFX-L PSU (A4-H2O A4 Black)

TL;DR I really like it. It's small, and still has more space than I thought. Easy to build in, even as a first-timer. Very much recommend it. The one I received was missing the PCIe riser cable and the power switch cable, but that may have been a reseller issue, not a manufacturing one. Components I Used: AMD Ryzen 7 7700 CPU ROG Strix B650Ei Gaming Wi-Fi Motherboard Ripjaws S5 DDR5-6000 32GB RAM (x2) WD_Black SN770 1TB NVMe SSD Drives (x2) ASUS Dual Radeon RX 6600 GPU Corsair H100i Hydro-Cooling Fan Corsair SF750 Power Supply Cooler Master PCIe 4.0 x16 riser cable* The Positives I love the design and model. It's even smaller than I expected, but it still holds a lot more space. For a case that's the size of a shoebox, the internal layout makes it easy to work with if you have the right parts. I still have room left over to add SATA SSD drives, or maybe even drop in a small figurine for fun. The ventilation is exceptional. There are vents on almost every side, and the panels are easy to pop off when needed, which helps with airflow and access. I have decent cooling components, and since this is a development machine and not a gaming rig, the system has stayed cool to the touch since I started using it. The case is very straightforward to work with. This was my first PC build, and the process went smoothly. I’d recommend this to anyone who wants a clean, sleek, utilitarian setup. The Negatives My unit was missing several components that were supposed to be included. There was no screw bag, and some of the screws for the top and bottom inner panels were missing. Most importantly, the PCIe riser cable wasn’t included, even though it’s shown in both the manual and the product listing. I had to buy a replacement for $40, though I did receive a partial refund. The power switch cable for the case's power button was also missing. Only a reset switch cable was included, so I had to short the power pins on the motherboard with a screwdriver to turn the system on. That's pretty bad. I eventually repurposed the reset switch cable to act as the power switch. It works, but that’s clearly a hack and not how it was intended to be used.

So small, so minimal, so beautiful. I love this case. It was so incredibly rewarding working within those confined limitations. Fit a 9070, 240 AIO Titan from Corsair, which fit without issue when the pump cap is off. Rog Loki PSU, which is a little big for this case, but was able to make it work with careful routing and some careful cutting and soldering of the longer PSU wires. Temps are great and noise level isn't bad, it can only fit 2 fans after all. Front panel arrived with a scratch and lian li sent out a replacement free of charge. This is the gold standard of ITX with water cooling

This case is absolutely amazing, punching well above its weight class. Let's start off with what I have inside mine -- an i7 12700K and am RTX 3090 TUF, powered by a Cooler Master V850 SFX PSU. Man, does this case make it happen. The H2O is able to handle this kind of power because the CPU is liquid-cooled, and the GPU sits on the other side of this sandwich style case. The case itself is rock solid, utilizing a near tool-less snap-together design and plenty of ventilation for its size. It is larger than the previous model (Dan A4 SFX), due to the intention of this being water-cooled. I opted for an MSI CoreLiquid 240R ARGB V2, since the water block is small and offers ARGB. It tames the temps well on my 12700K. You'll need to make sure your AIO will fit in this case, as there are many that won't -- either because the pump/water block is too tall or because the hoses are too thick. You'll also want something that has hoses on swivel elbows. Otherwise, routing the hoses and closing this case will be next to impossible. This was hands-down the hardest aspect of building in this case -- managing the AIO hoses. The A4-H2O gets a lot right. You can cool some higher end CPUs, use a full length GPU, and a semi-pleasant building experience. To top it off, it looks amazing, and the parts are high quality. Just keep your hands off the case, as the finish shows off fingerprints well. This case is an excellent competitor for the NR200, because it's 8 liters smaller, and has nearly all-metal construction. To me this one is the obvious choice. Also in this form factor I would avoid i9 CPUs entirely. They eat up too much power, and make too much heat. My experience with this case has been fantastic, but it did leave me wanting more. Having a liquid-cooled, 11.24-liter PC means it's going to be a tad heavy. It's also too big to fit into my DSLR camera bag. I also think this case's width dimension would be a tight fit in a carry on-size tough case like one from Pelican. If you need a small form factor PC for saving desk space, this is an excellent option. That's the niche this serves for me, and it delivers. Maybe you can make this a portable powerhouse for more than gaming. Its too big and heavy for me. Personally, I've found my 8.1-liter KXRORS S300 case to be a better road warrior, because it fits in my DSLR bag and weighs less. Sure, that one can't be as powerful, but it games very well, albeit a little louder.

This case is amazing for the vast majority of use cases, with the only flaws that I have seen coming from niche usage. First off, I am running this with a Ryzen 7 7800X3D, MSI Ventus RTX 4080, Asus B650E-I MB, 2x Gen 4 SSDs, Cooler Master H100x 240 AIO and a Cooler Master V850 SFX PSU. This case is great for most users, and plenty of other reviewers have listed its more relevant pros and cons, so I will focus mainly on one particular issue I had with it. The Thermals: Are great for the most part. There is one issue that I will mention below, but for most users, this probably won't matter. For all non m.2 thermal testing I am using a default fan curve with the B650E-I, and default fan curve with the 4080. No PBO/undervolt, just DOCP for memory. Temps are great for CPU and GPU, CPU never exceeding 80C in games, and only hitting close to TJmax in Cinebench, which is normal for this CPU. GPU never exceeded 65C in any game tested/played for an extended time. Backside M.2: The one thermal issue I have with my setup is M.2 Thermals. Tested with multiple gen 4 SSDs, multiple fan curves, 100% fan speed ect. I found that on the backside m.2, every gen 4 SSD I tested thermal throttled very hard, with any decent (>5GB) size file transfer. With the way the case is setup, The PCIe riser, blocks off most of the airflow that could go to the backside m.2 (see photo). The blue square shows where the riser normally rests when the case is fully assembled. This combined with close proximity to the GPU means that there is practically zero airflow to the back m.2. Also, with the way the motherboard cutout is, (at least for the Asus B650E-I and ASRock B550 Phantom ITX). The motherboard tray cutout is too small, in that you can not use the tray as a passive heatsink with a thermal pad (barely makes any contact see photos). But the cutout is also too big, in that you cant run any M.2 heatsink because it interferes. This makes using the backside m.2 with gen 4 practically useless. This might improve with gen 3, but do not have a gen 3 drive to test with. Dec 2025 Update. NOTE: Tested with Gen 3, and still had horrendous thermal throttling. The way I fixed this is by using a m.2 gen 4 extension and moving the ssd to the front of the case. This completely fixed the issue. Front M.2: While not nearly as bad as the backside, the frontside m.2 will still thermal throttle if you are moving enough files, or large enough files. Since there are no restrictions like the backside, I have tried different pads, drives with heatsinks, and using the stock Mobo heatsink, ect. The best result was running a slower, gen 4 drive(5GB/s), with the stock Mobo heatsink. I would not advise running a m.2 with a preinstalled heatsink, like a WD Black SN850x (like I have in the photo), it runs 66C at idle, with the rest of the system sitting at around or below 48C (idle). Overall: So, if you have the niche use case of needing a ton of fast m.2 storage, you might have to either pass on this case, get a motherboard with active m.2 cooling, or figure out some DIY solution, expanding the motherboard cutout and adding a heatsink, ect. Some Compatibility Notes: Modular PSUs are basically a MUST use in this case for large GPUs. I barely had any room left, using only necessary cables and had to order a direct 3x8 pin PCIe Power to 12VHPWR cable. If you use a PSU that doesn't have one, I.e. a 3x8PSU to 3x8 PCIe to a 3x8 PCIe to 12VHPWR adapter, you may have cable fitment issues. I was able to run the system using an adapter for a while, but when I heard about the 12VHPWR issues with bent cables, I just ordered the cable. I now have a lot more room in the bottom of the case, and less bend at my 12VHPWR connector. I would not recommend the Cooler Master H100x AIO if you are running a large GPU. I got it on sale, and regret buying it for this case. The tubes have to be oriented to the front of this case and are almost to large to fit with my GPU (see photo), and have an awkward bend in them to fit at all. Also, cable management in this case is rough, and the RGB that I don't even use that came with this AIO was extremely long and horrendous to manage.

This is now the best case I have ever owned. Super small, quiet, aesthetically pleasing, well built. Thermals (and noise - Noctua fans...) are better than you would expect with such a cramped case. This case is also surprisingly quiet. Get custom cables if you can, this will aid with cable management. Modular PSU's are a must with this case, non modular PSU's will not work as there is not enough room for spare cables. This case replaces my excellent Corsair 250D that is large for a ITX case but has excellent thermals. This machine is used for gaming on a 2K monitor. Easy to build as all of the panels are removable. CPU: Intel Core i5 13600K (not overclocked) never gets above 55-62C (better cable management or custom cables would probably improve this to drop below 60C) CPU Cooler: NZXT Kraken X52 (long hoses but they fit fine) with 2 Noctua 120mm x 25MM fans pushing out and 1 120mmx15mm slim Noctua fan on the bottom pulling air in. This fan is not mounted as there is not a mount in this spot however, it works fine and does not move at all. GPU: RTX 4070FE - (not overclocked) Stays at 70C or below. Very quiet. PSU: 850watt Cooler Master fully modular SFF 2 M.2 drives, no 2.5 SSD, don't need them anymore.

It's the perfect case for my needs: - Small even for SFF standards. - Quality materials. - Decent cooling options given the space you have. - Fits a pretty big GPU. - Supports air cooling if you pick the right size. Extra Notes: - I'm undervolting my 7700X and the fans are inaudible during day to day use, but do get a high quality fan if you go with air cooling. - Cable management is the trickiest part, as others have said. It's best if you pick a PSU that is known to work well with the stock cables it comes with or get custom cables. - It was easier to build in than my last mATX case, simply because you are more limited to parts and compatibility, but you must do research to build in this case. Do not just throw seemingly compatible parts in your Amazon cart. Validate that someone has built successfully with those parts first.

This case is very attractive. It’s so tiny. You can fit a lot of horse power in this tiny case. Even though it’s tiny it still has sufficient cooling. The 4070 Super looks extremely tiny in this case. You can fit much bigger graphics cards. Update: I have had this case for a little more than 5 months. The temperatures have been great. My i5 13600k accompanied by a Kraken 240mm AIO, has never gone over 73C while gaming and any other tasks. Typically the 13600k will be around 34C while idling and around 67C while doing heavy extensive tasks. My 4070 Super will not go over 70C while gaming, it usually hovers around 64C while gaming. This case has no problem keeping temps under control. Sure, you can get better temps with a case that is larger in volume, but you can't beat the form factor that this case has. That is a tradeoff that I am willing accept. another thing to note is that my PC doesn't get incredibly loud. It's not audible while idle and doing web and streaming. This case has been a dream come true. It is very attractive and is very good at keeping temps under control. This is a true SFF and you would not go wrong with this case.

I’ve been shopping around for a good ITX case for months and have been having a serious problem finding something that can fit a large enough cooler to allow my 9700x to stay cool while encoding at 100% usage. This case finally did it with a liquid cooler master atmos 240aio. Even with overclocking im not getting CPU temps above 75°C! on other cases with air coolers they were becoming heat soaked and reaching temps upwards of 95°C. I also fit a full SF750L PSU in this thing that’s way better than the low efficiency unreliable mini itx flex PSU. Lian Li did a great job with this case. So many cards are applicable with it and it’s small enough to carry in a pelican case. It’s not what I was originally going for with my build but ended up being necessary with the amount of load I run through my PC. The hardest part was routing the AIO cooler lines. I definitely would recommend for the price!

I cannot tell how good The case is. Looks premium and can fit large 3080ti perfectly. I have build it with low profile air cooler as I didn’t want to use AIO. The temps are really good and u am having no issues at all. Most importantly you can fit it in a backpack. Portability is awesome.

La cajita una pasada, un poco cara pero se paga el premium de marca y tamaño. La tuve que devolver porque la caja necesita estar ubicada en un espacio abierto (normal, nada especial) y en mi caso particular la quería para tener un ordenador potente pero pequeño en la tele del comedor, ubicada en un espacio cerrado, con lo cual la ventilación era nula y los componentes se me calentaban al ponerme a jugar a pesar de la refrigeración líquida. La tuve que devolver la caja para comprar otra con entrada de aire/ventiladores en el frontal tras 2 semanas probando mil cosas porque no había manera de contener las temperaturas y desgraciadamente el embalaje original fue tirado por error ya que siempre me guardo todo religiosamente durante 1 mes. El vendedor (tercero) me abonó poco más de la mitad del importe sólo por esto a pesar de devolver el producto de manera impoluta, pero Amazon, como siempre, arregló la situación tras reclamar. Así da gusto.

Wer auf der Suche nach einem kompakten, aber extrem leistungsstarken Small-Form-Factor-System (SFF) ist, kommt an diesem Gehäuse kaum vorbei. Das LIAN LI A4-H2O hat mich auf ganzer Linie überzeugt. Design & Optik: Das Zusammenspiel aus schwarzem SPCC-Stahl und gebürstetem Aluminium sieht absolut hochwertig und edel aus. Es ist minimalistisch, zeitlos und macht auf jedem Schreibtisch eine verdammt gute Figur. Die Verarbeitung ist, wie von Lian Li gewohnt, erstklassig. Einbau & Bestückung: Trotz des extrem geringen Volumens (ca. 11 Liter) lässt sich das Gehäuse super bestücken. Das clevere Drei-Kammer-Layout sorgt dafür, dass man die Komponenten logisch und ohne Frust unterbringt. Das Gehäuse lässt sich von fast allen Seiten öffnen (Paneele sind gesteckt), was den Zugang beim Schrauben massiv erleichtert. Der Einbau einer 240mm-All-in-One-Wasserkühlung (AIO) für die CPU geht reibungslos vonstatten. Dank des mitgelieferten PCIe 4.0 Riser-Kabels findet selbst eine große Triple-Slot-Grafikkarte problemlos auf der Rückseite Platz. Fazit: Außen kompakt und edel, innen ein echtes Raumwunder. Der Hardware-Einbau macht trotz des engen Raums richtig Spaß. Eine absolute Kaufempfehlung für jeden ITX-Enthusiasten!

Pas ultra facile à monter mais résultat final incroyable pour une taille si compacte, vraiment un boitier incroyable que je recommande

Honestamente estaba aferrado a algo como el fractal design ridge pero como no llega a México me decidí por este y honesta mente es muy bueno considerando que puedes meterle más de 1 ssd no lo dice oficialmente pero donde montas una ssd puedes puedes poner una bahía de 2 y así tienes 1 ssd mas también donde está el orificio para hacer espacio a la grafica puedes insertarlas maximo 2 con presión de nuevo nada de esto es oficial pero es otra manera de hacer todo el espacio eficiente y en se tener más almacenamiento, espero les haya servido (no es mío oficialmente es de un yutubero ingles)