What is the impact of supply tightness on Q3 gross margin? 
t say, we are so well-positioned on the edge and the 5G.
The open RAN, VRAN initiatives in the industry are now hitting stride. And I think I've only been on three major service provider calls this week on exactly that topic, right, where they're really starting to look at those deployments at scale for a standardized software-driven edge environment for their 5G networks. And I'd also say this is a victory for innovation. Just a year ago, we were very -- just three years ago, there was grave geopolitical concerns around 5G and would there ever be flexibility for how that would get deployed nationally.
Now everybody is aligning against the ORAN, VRAN initiatives as the way to do their 5G broad deployments. And the Intel platform sits in the center of those almost everywhere in the world. It really is a great success story for us and one that we think that we'll be harvesting for many, many years to come. 
Harlan Sur -- J.P. Morgan -- Analyst
Thank you.
Operator
Thank you. Our next question comes from the line of Toshiya Hari from Goldman Sachs. Your question, please.
Toshiya Hari -- Goldman Sachs -- Analyst
Good afternoon. Thanks so much for taking the question. I had a multi-part question on gross margin. George, you talked about PRQ reserves related to Alder Lake being a headwind this quarter.
If you can quantify that for us, ballpark, that would be super helpful. And then, toward the end of your remarks, in terms of the second half outlook, in terms of gross margin, you talked about supply tightness driving a deterioration in CCG mix. I was a little surprised to hear that given how strong Chromebooks were in the first half. So if you can elaborate on that that would be super helpful as well.
Thank you.
George Davis -- Chief Financial Officer
Yeah, so in terms of -- if we're looking at the -- particularly, let's look at Q3 because that's where we discussed the Alder Lake pre-PRQ reserves. It's one of the two top movers. When you look at being down 400 basis points, certainly, it's not the majority, but it's a meaningful impact in the quarter. Seven-nanometer start-up costs ramping is the biggest impact far and away.
In terms of supply tightness, the challenge is -- part of what made Q2 so great was customers really challenged our sales teams and our factories to remix within a quarter to provide them with the components that they could then match with what their supply chain was providing them so they could get to market. And this was -- watching it was super impressive, a little bit scary at times. But the team did a fantastic job. So we did a really good job of eating up a lot of our substrates, some of which we thought we would have available to us in Q3.
So the supply impact is more of a volume impact. Customers are already starting to mix upwards. So that's usually a positive for gross margin. And if there's upside in the second half, it will come from both higher substrates and the ability and a higher mix.
And that could well be the case. We were cautious. Q3, we could see we had a real supply challenge. I mean, it's acute.
But Q4, we are doing everything we can to help our substrate suppliers increase supply, including finishing up some of their manufacturing in our own facilities, which is something we could do as an IDM. If we have more success than we can forecast today, maybe Q4 could be seen as conservative. 
Toshiya Hari -- Goldman Sachs -- Analyst
Thank you.
Operator
Thank you. Our next question comes from the line of Srini Pajjuri from SMBC Nikko. Your question, please.
Srini Pajjuri -- SMBC Nikko SecuritiesAnalyst
Thank you. Just to follow up to the previous question, George. Could you give us some idea as we head into the next year, what are some of the puts and takes on the gross margin front? I'm just curious as to how long the seven-nanometer cost will persist and when do they peak out. And as we go into first half of next year, how should we think about the gross margins?
George Davis -- Chief Financial Officer
Yeah, so again, I'm going to defer any kind of forecasting of '22 and beyond. But as yo
t say, we are so well-positioned on the edge and the 5G.
The open RAN, VRAN initiatives in the industry are now hitting stride. And I think I've only been on three major service provider calls this week on exactly that topic, right, where they're really starting to look at those deployments at scale for a standardized software-driven edge environment for their 5G networks. And I'd also say this is a victory for innovation. Just a year ago, we were very -- just three years ago, there was grave geopolitical concerns around 5G and would there ever be flexibility for how that would get deployed nationally.
Now everybody is aligning against the ORAN, VRAN initiatives as the way to do their 5G broad deployments. And the Intel platform sits in the center of those almost everywhere in the world. It really is a great success story for us and one that we think that we'll be harvesting for many, many years to come. 
Harlan Sur -- J.P. Morgan -- Analyst
Thank you.
Operator
Thank you. Our next question comes from the line of Toshiya Hari from Goldman Sachs. Your question, please.
Toshiya Hari -- Goldman Sachs -- Analyst
Good afternoon. Thanks so much for taking the question. I had a multi-part question on gross margin. George, you talked about PRQ reserves related to Alder Lake being a headwind this quarter.
If you can quantify that for us, ballpark, that would be super helpful. And then, toward the end of your remarks, in terms of the second half outlook, in terms of gross margin, you talked about supply tightness driving a deterioration in CCG mix. I was a little surprised to hear that given how strong Chromebooks were in the first half. So if you can elaborate on that that would be super helpful as well.
Thank you.
George Davis -- Chief Financial Officer
Yeah, so in terms of -- if we're looking at the -- particularly, let's look at Q3 because that's where we discussed the Alder Lake pre-PRQ reserves. It's one of the two top movers. When you look at being down 400 basis points, certainly, it's not the majority, but it's a meaningful impact in the quarter. Seven-nanometer start-up costs ramping is the biggest impact far and away.
 In terms of supply tightness, the challenge is -- part of what made Q2 so great was customers really challenged our sales teams and our factories to remix within a quarter to provide them with the components that they could then match with what their supply chain was providing them so they could get to market. And this was -- watching it was super impressive, a little bit scary at times. But the team did a fantastic job. So we did a really good job of eating up a lot of our substrates, some of which we thought we would have available to us in Q3.
So the supply impact is more of a volume impact. Customers are already starting to mix upwards. So that's usually a positive for gross margin. And if there's upside in the second half, it will come from both higher substrates and the ability and a higher mix.
And that could well be the case. We were cautious. Q3, we could see we had a real supply challenge. I mean, it's acute.
But Q4, we are doing everything we can to help our substrate suppliers increase supply, including finishing up some of their manufacturing in our own facilities, which is something we could do as an IDM. If we have more success than we can forecast today, maybe Q4 could be seen as conservative. 
Toshiya Hari -- Goldman Sachs -- Analyst
Thank you.
Operator
Thank you. Our next question comes from the line of Srini Pajjuri from SMBC Nikko. Your question, please.
Srini Pajjuri -- SMBC Nikko SecuritiesAnalyst
Thank you. Just to follow up to the previous question, George. Could you give us some idea as we head into the next year, what are some of the puts and takes on the gross margin front? I'm just curious as to how long the seven-nanometer cost will persist and when do they peak out. And as we go into first half of next year, how should we think about the gross margins?
George Davis -- Chief Financial Officer
Yeah, so again, I'm going to defer any kind of forecasting of '22 and beyond. But as yo