Thank you for joining us today. Now we are going to review the financial numbers of Q4. Q4 revenue was TWD 114.2 billion, representing a 14% year-on-year growth and a 2% sequential increase. Q4 GP margin saw a 16% year-over-year increase, but experienced a 10% sequential decline, primarily due to the seasonal variations in the product mix and the normalization of inventory provisions. GP margin in Q4 was 30.8% versus 30.4% a year ago and 34.9% in Q3. If we look at the segmentation performance, year-over-year, infrastructure and power electronics saw the strongest revenue growth, driven by solid data center demand, and automation showed steady improvement from a low base. However, mobility continued to struggle due to the market weakness.
Quarter- over- quarter, thanks to the robust demand in data center business, we found the fastest sequential growth in the infrastructure segment, while automation also saw moderate improvement. Meanwhile, power electronics experienced a slight seasonal decline, and mobility remained lackluster . Earnings-wise, except for mobility, which saw a year-on-year profit contraction, the other three segments showed a varying degree of profit improvement compared to a year ago. Sequentially, most segments experienced a profit correction from the previous quarter, while the infrastructure segment saw significant profit expansion, driven by the expanding scale of data center business. In Q4, we had a TWD 900 million non-operating loss, which was mainly due to the impairment loss of investments. Q4's non-operating expenses related to foreign exchange were mainly driven by the hedging costs.
In Q4, we had TWD 9.8 billion profit before tax, down 24% year-on-year and 44% quarter-on-quarter. Q4 EBITDA was TWD 17 billion, down 11% year-on-year and 30% quarter-on-quarter. Q4 tax expense was about 2.9, sorry, 2.5 billion dollars, representing a 25.6% effective tax rate. However, the increase was mainly because the impairment losses were not tax deductible. Otherwise, our tax rates are relatively stable. So net profit after tax was about TWD 7.2 billion, down 20% year-on-year and 42% quarter-on-quarter. So Q4 EPS was 2.76. And then now we have a look at the accumulated numbers for the whole year. The revenue was TWD 421.1 billion in 2024, up 5% from a year ago. GP was up 17% year-on-year with a GP margin of 32.4% versus 29.2% a year ago.
In terms of the operating expenses, in 2024, R&D expenses increased by 15%, while SG&A expenses grew by 18% over the same period, so the total OpEx grew by 17% versus a year ago, so consequently, the OpEx ratio expanded to 21.1%, up from 19% a year ago, and OP margin was 11.3% compared to 10.2% a year ago. In terms of the segmentation performance, we found the fastest growth in power electronics, mainly driven by the robust demand in passive component business. The other three segments, however, remained relatively flattish compared to the previous year. Earnings-wise, both power electronics and infrastructure showed significant profit improvement year-over-year, while automation and mobility faced some profit contraction due to the pretty lackluster underlying market demand. Non-operating profit dropped to TWD 3.7 billion from TWD 7.7 billion in 2023.
In total, we had TWD 51.3 billion pre-tax income, up 5% from a year ago. Our EBITDA was TWD 77.9 billion, up 9% from a year ago. The tax expense was around TWD 10.9 billion, representing a 21.3% effective rate, and the non-controlling interest was TWD 5.2 billion versus TWD 5.5 billion a year ago. Therefore, the net profit after tax in 2024 was TWD 35.2 billion versus TWD 33.4 billion a year ago. The EPS of 2024 was 13.6 versus 12.686 a year ago, marking a 5% increase from the previous year. The proposed cash dividend this year is TWD 7 per share. Now we are going to the Q&A session. The first question is going to relate to the outlook for Q1, and my second question is related to the demand outlook for AI servers.
And the third one is, could you please give us any color related to the tariff impact? So for your first question, I think, at least in the second, sorry, in the first half of this year, we are actually anticipating a pretty strong demand, or at least from the data center-related business, but it's still, there are still some uncertainties in the supply chain. So for your second question, indeed, we are anticipating strong demand from this AI servers, but still, there are some uncertainties which are out of our control. And then I can add on the AI server demand.
If you look at the CapEx plans, especially from the CapEx plans of those, I mean, big four hyperscalers in the U.S., their CapEx actually, instead of, I mean, decreasing or declining, their CapEx for the AI deployment is actually still increasing. That's the reason why we are relatively positive on the AI server outlook. The next question is, what is the outlook for your EV business this year? Will the losses continue? And then can you also give us, I mean, more details about how do tariffs really impact the company? For example, could you please, like, share some breakdowns in terms of your capacity, especially, I mean, the production capacity, especially related to the AI server products? I'm going to answer your questions one by one.
First of all, although our EV components business experienced a sharp decline in demand in Q4 last year, leading to lower capacity utilization and higher inventory levels, resulting in a slight loss. Moreover, many major automakers face increasing challenges from tariffs and many other factors. In the short run, this is one of the most difficult and uncertain businesses for us. But in the long run, we still believe that the penetration rate of EV is still going to increase in the longer run. I think there is still a pretty long way to go for the whole EV market development.
In terms of your second question related to our production plans for our liquid cooling business, in terms of the cooling components and other mechanical parts, they are mainly still I mean manufactured in China because there is I mean a pretty comprehensive I mean mechanical supply chain in China, also considering the overall cost in terms of the manufacturing cost. But we are also planning to increase our capacity for the liquid cooling components in Thailand. And then for the final assembling, we are also trying to provide some capacity in the U.S. in order to handle these tariff issues for the final assemblies.
But if, I mean, considering the cost issue, if we are not really able to, I mean, make all the final assembling in the U.S., then Taiwan and Thailand are also locations we are considering to do the final assembling for these AI-related products. So I think there are actually four questions, I mean, from your end. So the first one is related to our telecom power business, and the second one is related to our networking business. And the third one is related to our CapEx plan for this year. And then the final one is related to the lawsuit, related to our DC-DC converter business. So maybe I just answered the four questions first. So here, I mean, at Delta, what we do with this, the patent management, actually, we take this very, very seriously.
Whenever we try to, I mean, develop a new product, we always do a very comprehensive patent research. And then besides the internal patent research, we also hired an external law firm and asked for their professional opinion on the IP protection. But even though we always manage to do a very comprehensive patent research before we launch a new product, there are still many things and uncertainties which are outside of our control. In terms of the latest final ITC ruling in Vicor lawsuit, of the three items in the ITC case, only one was clearly unfavorable to us. Another was slightly unfavorable. The last one was dismissed.
So if the ITC ruling is confirmed, the U.S. president still has 60 days to decide whether to issue an executive order banning the affected products from entering the U.S. However, because we have prepared for this lawsuit, and if the affected products are banned, we have alternative designs to offer customers. Since the related revenues are a pretty tiny percentage of our total revenues, we do not expect a significant impact on our operations in the short term. But in a nutshell, I think, as I mentioned earlier, it's not going to actually impact our revenues or the business. I mean, it's not going to impact our business significantly, I mean, in the short term, because we have already, I mean, proposed the new designs or redesign products to customers.
For your second question, which is related to the CapEx plan this year. Because we are still, I mean, investing heavily in factory automation, expanding production lines, and constructing new facilities, CapEx remains at a relatively high level. However, last year we purchased several office buildings, and unless there are unexpected developments, this expense should decrease, I mean, this year. As a result, the CapEx is unlikely to increase compared to last year. A similar trend may continue into the next few years. We will adjust based on the long-term market demand. Speaking of our networking and telecom businesses, I think they faced a pretty challenging year in 2024, with the revenue declining by about 20%.
This was primarily due to a high base from the previous year and weak enterprise demand under a high interest rate environment. Currently, as the base has significantly lower, this business has returned to positive growth. However, we cannot yet say that the demand is strong. The situation is somewhat similar to what we are seeing in the industrial automation and building automation businesses. The next question is related to the AI component supply chain. From our understanding, I heard about there are some bottlenecks in the supply chain, which somewhat delay the shipment of AI servers. Could you please, I mean, share any, give us any color on the supply chain bottlenecks or supply chain issue? Because we are not the, I mean, the assembler.
So, I don't think this question—I mean, we are the right one to answer this question. I think you better to ask the EMS company that is responsible for assembling AI servers. So how should we expect expenses to trend this year? Were there any one-time factors behind the significant increase in Q4 expenses? I think compared to 2024, sorry, compared to 2023, sales and marketing trade shows in 2021 are returning to pre-pandemic levels, contributing to higher costs. In 2025, we still have many investments planned, so expenses will continue to rise. However, if revenue growth accelerates, the expense ratio may actually decrease instead of increase. This remains one of our key focus areas. In terms of the reasons, I mean, behind the large impairment recognized in Q4, I think our accounting principles are very conservative.
Every year, we review whether intangible assets and goodwill need to be reassessed and impaired. Due to last year's challenging macro environment, some subsidiaries we acquired years ago struggled, even though our overall performance was supported by the data center business. As a result, we adjusted certain assumptions, lowered the valuation of related intangible assets and goodwill, and recognized a significant impairment. After these adjustments, even if it takes time for these subsidiaries to generate synergies, I think further large impairments should not be necessary. The next question is related to the profitability of your EV business. How should we expect the profitability of your EV business going forward, considering the obvious headwinds in the EV market currently?
I think, even though we actually saw a slight, modest, I mean, loss in our EV business in Q4, but still, if you look at the whole year, we still managed to maintain some minimal profit for our mobility business. Even though, if you look at the inventory level in Q4, we are seeing some increasing inventory from this EV business, but still, I think that is not really going to be a very big problem because this is just because of the current headwinds in the EV market. But, as soon as, I mean, the market is going back to or resume to a normal level, then when we are able to ship our components, then I think we are able to reverse some of the inventory provisions from the, I mean, the previous inventory provisions for the EV business.
The next question is related to the air - sorry, liquid cooling business as a percentage of year-to-date revenues last year. Then also another question is, what is the percentage, I mean, in terms of your AI server powers as a percentage to the total revenues. In terms of the liquid cooling business, last year, I think it was less than 1% of our revenues. This year, especially in January, it has already reached like 6% or somewhere between 6%-7% of our monthly revenues. For the AI powers, I think it is more difficult to define, because it is actually quite challenging to define whether this power product is for AI servers or not. We do not really have a very accurate percentage for the AI server components.
So what are your targets for your EV business this year? I think for this year we are targeting to at least maintain a flattish level compared to the previous year because we haven't really seen any signs of, I mean, recovery in the underlying market. So what are the growth targets for your power business and your ICT business? I think we are not really able to provide any financial forecasts for our businesses. But just, I mean, look at the demand, I mean, the market demand. I think our power business and our ICT business are obviously supported by the strong data center demand this year. But we are just not really able to provide the financial forecast in terms of the accurate numbers.
Could you please share your expectations in terms of your top-line growth this year, and also your GP margin and OP margin profiles? So first of all, I think in terms of the top-line growth, we are always targeting double-digit growth every year. But just, there are always so many uncertainties. So sometimes, we meet our target, but sometimes we don't. Okay. So my next question is, could you please share any updates on the AI data center? I mean, on the AI architecture changes in the AI servers, especially on the power side? So I think because the power management has become an increasingly critical issue for the AI servers.
I think both the customers and the suppliers like us are trying our best to optimize the architecture in order to make the whole servers or products more efficient. There are actually many layers to achieve this goal. For example, there are the facility level and rack level, and then also the board level. But still, the market itself is still evolving. Different companies and different designers actually have different thoughts on their product development. It's really hard to have a concrete answer for the new design for new generations of AI server products. Can you please share the percentage, I mean, the aggregate percentage of your power, I mean, the power server power products plus your BBU-related products and UPS products, and also your cooling products and cooling components for the AI servers?
I think, as I said, we don't really, I mean, have these numbers or detailed numbers for each business. I think, generally speaking, all those, I mean, related products, could be over like 10% of our total sales. But to be honest, I don't really have the detailed ratio at the moment. The next question is, could you please share your plans or your ambitions on the hydrogen energy business? I think our focus is. We actually focus on two solutions in terms of this hydrogen energy. One is SOEC, and the other one is SOFC. So both of them are related to the microgrid application. So they are either for generating the green hydrogen or they are either for, I mean, power generation.
So we are actually quite ambitious on this, I mean, hydrogen energy because we do believe the microgrid is actually the trend for future to support more the resilient power generation network. So we actually have quite a massive investment in terms of the license transfer from the U.K. company, with an amount like $60 million - $70 million, including the patent to licensing the patents from this company. And then in terms of the humanoid robots, I think for the robots or, I mean, the robots used in the factories are pretty mature, I mean, right now. So I suggest we are talking about the service robots. So I think the key point here is not really about whether or not we can manufacture or assemble the humanoid robots.
It's more about, I mean, for those kind of, I mean, service robots, they have to interact with human beings directly. So they are going to have, I mean, to have, I mean, many new regulations regarding how service robots that could, I mean, interact with the human beings in a place. But with the help of, I mean, generative AIs, we do believe that this is going to happen in the future. But as I said, whenever, I mean, the humanoid robots, which are basically, I mean, essentially machine, whenever they have to, I mean, have any interaction with the human beings, there must be regulations regulating how they really interact with human beings for the safety issues. So I think it's still a bit early to say.
So I think, in my personal opinion, I think it's still maybe, I mean, it still takes another 10 years to see this really happens. So I think it's probably not our near-term goal in the near term. I think we are almost running out of the time. So maybe we will just have the final, the last question from the audience. Could you please share your thoughts on how you see the outlook for your BA building automation business this year? Are there any, I mean, are there any impacts, I mean, from these tariff issues on your building automation business?
I think in terms of these tariff issues, even though we are not really handling or paying the tariffs by ourselves directly, but still, if our customers they have to pay those tariffs, I think definitely the customers will return to us and talk about the price reduction, or kind of share the cost in some way. So what we have to do is we actually try to continue to diversify our capacity and then to minimize the impact from these tariff issues and tariff exposure. And then in terms of our industrial automation, I think last year was probably the trough for this business. And this year, I do believe it's going to be better than last year.