expenses, derived from an increase in average research and development headcount of 487 employees and an increase in payroll costs, including share-based compensation. Additionally, there was an increase of $19 million in cloud computing services and investments attributable to new product development..
Research and development expenses, net, in the nine months ended October 1, 2022, increased by $175 million, or 45%, compared to the nine months ended September 25, 2021. This increase was primarily due to an increase of $119 million in payroll and related expenses, derived from an increase in average research and development headcount of 437 employees and an increase in payroll costs, including share-based compensation.Additionally, there was an increase of $37 million in cloud computing services and investments attributable to new product development.
Sales and Marketing Expenses
Sales and marketing expenses in the three months ended October 1 2022, decreased by $6 million, or 18%, compared to the three months ended September 25, 2021.
Sales and marketing expenses in the nine months ended October 1 2022, decreased by $7 million, or 7%, compared to the nine months ended September 25, 2021.
The decrease in both periods was mainly due to a decrease in amortization of customer relationship and brand-related intangible assets.
General and Administrative Expenses
General and administrative expenses in the three months ended October 1, 2022, increased by $1 million, or 13%, compared to the three months ended September 25, 2021. This increase was mainly due to IPO related expenses.
General and administrative expenses in the nine months ended October 1, 2022, increased by $1 million, or 4%, compared to the nine months ended September 25, 2021. This increase was mainly due to IPO related expenses, partially offset by a decrease in share-based compensation expenses.
Interest Income (expense) with related party and Other Income (expense), net
Interest expense, net in the three months ended October 1, 2022, increased by $6 million compared to the three months ended September 25, 2021.
Interest expense, net in the nine months ended October 1, 2022, increased by $13 million compared to the nine months ended September 25, 2021.
The increase in net interest expense in both periods was mainly due to accrued interest on the Dividend Note issued to Intel on April 21, 2022, partially offset by higher interest earned on a loan to Intel.
Other income (expense), net in the three months ended October 1, 2022, increased by $1 million, compared to the three months ended September 25, 2021. This increase in other income was mainly due to the increase in interest rate on short term bank deposits.
Other income (expense), net in the nine months ended October 1, 2022, increased by $6 million, compared to the nine months ended September 25, 2021. This increase in other income was mainly due to the increase in interest rate on short term bank deposits and the effect of foreign exchange fluctuations.
Benefit (Provision) for Income Tax
In the three months ended October 1, 2022, provision for income tax increased by $9 million, compared to the three months ended September 25, 2021. This increase was mainly due to growth in our overall business.