What is the estimated range for the SOC market size in 2021 
ng demand in the long dormant automotive test market with orders for our Eagle Test product lines surging. Smartphone shipments are expected to grow in 2021 after contracting about 10% in 2020 and 5G content should increase. On the other hand, the SOC test market in China will likely be down in 2021 due to the expanded and full year effects of trade restrictions that were widened in 2020. Also as always, tester demand from our largest customer will remain opaque until some time in Q2. Additionally, the global economic impact of COVID and its impact on electronics demand after a surge in 2020, It's hard to forecast with arguments for both positive and negative effects.
Taking all of that into account, we have a bit wider range in our SOC market size estimate for 2021 at $3.3 billion to $3.8 billion, up slightly from 2020 at the midpoint. In Memory Test, the transition to LPDDR5 and DDR5 should gain momentum in 2021 and beyond. After growing about 50% in 2020, we view the memory market to be in the $800 million to $1 billion range in 2021about even with 2020 at the midpoint.
In Storage Test, the underlying demand drivers of increased density and HDD and increased complexity in Semi Devices driving system level test remain in place. However, visibility is limited and annual shipments can be very lumpy. After more than tripling over the last 3 years, we expect 2021 sales to be in a band of plus or minus 20% from the 2020 level. For the rest of our test businesses, we expect growth in the 5% to 10% range in 2021. In Industrial Automation, 2021 is starting off on a strong footing. Barring any additional COVID related manufacturing sector shutdowns, we expect to deliver the highest ever first quarter sales in each of our automation businesses and we are well positioned to grow in excess of 30% for the year. 2020's results reflect well on Teradyne strategy, execution, and efficiency. Our test businesses show the successful results of R&D bets in years past, and enable us to increase those bets for the future. Our industrial automation investments continue undeterred by short-term impacts of COVID and we are well positioned to capitalize on a world emerging to invest even more in automation to improve resilience and productivity. Equally significant, 2020 shows the resilience of Teradyne employees, our global suppliers, and our operating model. In the face of unimaginable challenges across communities worldwide, the team dealt with health, safety, and operation obstacles daily, met R&D milestones, executed steep new product ramps, and delivered record shipments of SOC, memory and storage test products to meet our customers' needs. We did all this while exercising the cost and schedule discipline expected at Teradyne. This is truly extraordinary and I am very grateful to be part of such a powerful team.
As we move into 2021, the outlook appears bright across all our markets. As Sanjay will detail, we are returning to our share repurchase program and have an active M&A pipeline. As 2020 taught us, no matter what comes our way in the short term, I am confident our global team and market strategy will deliver exciting long-term returns for our customers, investors, and employees. Sanjay will now take you through the financial and modeling details. Sanjay?
Sanjay Mehta -- Vice President, Chief Financial Officer
Thank you, Mark. Good morning, everyone. Today, I'll cover the financial highlights of Q4 and review the financial details of 2020. Looking forward, I'll provide our Q1 outlook, an update to our mid-term earnings model, and our capital allocation plans. Now to Q4.
Revenues were $759 million, which were $19 million above the high end of the guidance range. We delivered a non-GAAP operating profit of 30% and EPS of $1.10. Semi Test revenue of $524 million was driven by SOC and Memory Test demand enabling 5G handsets and higher speed flash and DRAM devices. System test group had revenue of $104 million down quarter-over-quarter driven by lower Storage Test shipments. Industrial automation or IA revenue of $92 million had a seasona
ng demand in the long dormant automotive test market with orders for our Eagle Test product lines surging. Smartphone shipments are expected to grow in 2021 after contracting about 10% in 2020 and 5G content should increase. On the other hand, the SOC test market in China will likely be down in 2021 due to the expanded and full year effects of trade restrictions that were widened in 2020. Also as always, tester demand from our largest customer will remain opaque until some time in Q2. Additionally, the global economic impact of COVID and its impact on electronics demand after a surge in 2020, It's hard to forecast with arguments for both positive and negative effects.
Taking all of that into account, we have a bit wider range in our SOC market size estimate for 2021 at $3.3 billion to $3.8 billion, up slightly from 2020 at the midpoint. In Memory Test, the transition to LPDDR5 and DDR5 should gain momentum in 2021 and beyond. After growing about 50% in 2020, we view the memory market to be in the $800 million to $1 billion range in 2021about even with 2020 at the midpoint.
 In Storage Test, the underlying demand drivers of increased density and HDD and increased complexity in Semi Devices driving system level test remain in place. However, visibility is limited and annual shipments can be very lumpy. After more than tripling over the last 3 years, we expect 2021 sales to be in a band of plus or minus 20% from the 2020 level. For the rest of our test businesses, we expect growth in the 5% to 10% range in 2021. In Industrial Automation, 2021 is starting off on a strong footing. Barring any additional COVID related manufacturing sector shutdowns, we expect to deliver the highest ever first quarter sales in each of our automation businesses and we are well positioned to grow in excess of 30% for the year. 2020's results reflect well on Teradyne strategy, execution, and efficiency. Our test businesses show the successful results of R&D bets in years past, and enable us to increase those bets for the future. Our industrial automation investments continue undeterred by short-term impacts of COVID and we are well positioned to capitalize on a world emerging to invest even more in automation to improve resilience and productivity. Equally significant, 2020 shows the resilience of Teradyne employees, our global suppliers, and our operating model. In the face of unimaginable challenges across communities worldwide, the team dealt with health, safety, and operation obstacles daily, met R&D milestones, executed steep new product ramps, and delivered record shipments of SOC, memory and storage test products to meet our customers' needs. We did all this while exercising the cost and schedule discipline expected at Teradyne. This is truly extraordinary and I am very grateful to be part of such a powerful team.
As we move into 2021, the outlook appears bright across all our markets. As Sanjay will detail, we are returning to our share repurchase program and have an active M&A pipeline. As 2020 taught us, no matter what comes our way in the short term, I am confident our global team and market strategy will deliver exciting long-term returns for our customers, investors, and employees. Sanjay will now take you through the financial and modeling details. Sanjay?
Sanjay Mehta -- Vice President, Chief Financial Officer
 Thank you, Mark. Good morning, everyone. Today, I'll cover the financial highlights of Q4 and review the financial details of 2020. Looking forward, I'll provide our Q1 outlook, an update to our mid-term earnings model, and our capital allocation plans. Now to Q4.
Revenues were $759 million, which were $19 million above the high end of the guidance range. We delivered a non-GAAP operating profit of 30% and EPS of $1.10. Semi Test revenue of $524 million was driven by SOC and Memory Test demand enabling 5G handsets and higher speed flash and DRAM devices. System test group had revenue of $104 million down quarter-over-quarter driven by lower Storage Test shipments. Industrial automation or IA revenue of $92 million had a seasona